Methods and apparatus for launching or receiving electromagnetic waves

ABSTRACT

Aspects of the subject disclosure may include, a system configured for generating a signal, and inducing, by a coupler, an electromagnetic wave that propagates along a physical transmission medium. The coupler can be configured to convert the signal into a plurality of wave modes that combine to form the electromagnetic wave having an electromagnetic field configuration that reduces leakage of the electromagnetic wave as the electromagnetic wave propagates along the physical transmission medium. Other embodiments are disclosed.

STATEMENT REGARDING SPONSORED RESEARCH OR DEVELOPMENT

The Government has rights in this invention pursuant to the StrategicPartnership Project Agreement ([17-047]) between Stanford University andAT&T Services, Inc.

FIELD OF THE DISCLOSURE

The subject disclosure relates to methods and apparatus for launching orreceiving electromagnetic waves.

BACKGROUND

As smart phones and other portable devices increasingly becomeubiquitous, and data usage increases, macrocell base station devices andexisting wireless infrastructure in turn require higher bandwidthcapability in order to address the increased demand. To provideadditional mobile bandwidth, small cell deployment is being pursued,with microcells and picocells providing coverage for much smaller areasthan traditional macrocells.

In addition, most homes and businesses have grown to rely on broadbanddata access for services such as voice, video and Internet browsing,etc. Broadband access networks include satellite, 4G or 5G wireless,power line communication, fiber, cable, and telephone networks.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 is a block diagram illustrating an example, non-limitingembodiment of a guided-wave communications system in accordance withvarious aspects described herein.

FIG. 2 is a block diagram illustrating an example, non-limitingembodiment of a transmission device in accordance with various aspectsdescribed herein.

FIG. 3 is a block diagram illustrating an example, non-limitingembodiment of a guided-wave communications system in accordance withvarious aspects described herein.

FIG. 4 is a block diagram illustrating an example, non-limitingembodiment of a waveguide system in accordance with various aspectsdescribed herein.

FIG. 5A is a block diagram illustrating an example, non-limitingembodiment of a communication system in accordance with various aspectsdescribed herein.

FIG. 5B is a block diagram illustrating an example, non-limitingembodiment of a portion of the communication system of FIG. 44A inaccordance with various aspects described herein.

FIG. 5C is a graphical diagram illustrating an example, non-limitingembodiment of downlink and uplink communication techniques for enablinga base station to communicate with communication nodes in accordancewith various aspects described herein.

FIG. 5D is a graphical diagram illustrating an example, non-limitingembodiment of a frequency spectrum in accordance with various aspectsdescribed herein.

FIG. 5E is a graphical diagram illustrating an example, non-limitingembodiment of a frequency spectrum in accordance with various aspectsdescribed herein.

FIG. 6 is a block diagram illustrating an example, non-limitingembodiment of a communication system that utilizes beam steering inaccordance with various aspects described herein.

FIG. 7A1 is a graphical diagram illustrating, an example, non-limitingembodiment of an eigenmode simulation with metal wire (orange), vacuum(blue) and PML (pink) in accordance with various aspects describedherein.

FIG. 7A2 is a graphical diagram illustrating, an example, non-limitingembodiment of an electric field magnitude for a 20 GHz Sommerfeld wavepropagating on a 5 mm radius copper wire in accordance with variousaspects described herein.

FIG. 7A3 is a graphical diagram illustrating, an example, non-limitingembodiment of large radius simulations comparing radial and longitudinalelectric field between theory and simulation in accordance with variousaspects described herein.

FIG. 7B is a graphical diagram illustrating, an example, non-limitingembodiment of T3P scaling on NERSC Cori computer in accordance withvarious aspects described herein.

FIG. 7C is a graphical diagram illustrating, an example, non-limitingembodiment of a model generated using a mesh merging tool to generate 50m wire meshes by merging ten 5 m models. A moving window technique andpulse excitation was utilized to reduce the computation time for the 50m wire in accordance with various aspects described herein.

FIG. 7D is a graphical diagram illustrating, an example, non-limitingembodiment of electric field plots for an example of (a) S3P simulationfor the TM₀ mode with a simulation radius R=200 mm, wire L=10 m, r=5 mm,σ=5.8e7s/m at 5 GHz; (b) XY plane at input; and (c) Close up of wire; XZplane over 10 m span showing curvature of wire in accordance withvarious aspects described herein.

FIG. 7E is a graphical diagram illustrating, an example, non-limitingembodiment of a radial electric field intensity along a 10 meter 0.5 cmradius lossless wire excited by Sommerfeld TM₀ mode at 30 GHz inaccordance with various aspects described herein.

FIG. 7F is a graphical diagram illustrating, an example, non-limitingembodiment of an experiment to measure transmission on single conductorwire fed by tapered waveguide horns. The horns were separated by adistance of approximately 10 meters in accordance with various aspectsdescribed herein.

FIG. 7G is a graphical diagram illustrating, an example, non-limitingembodiment of a TEM mode transmission versus frequency through coax feedand horn in accordance with various aspects described herein.

FIG. 7H is a graphical diagram illustrating, an example, non-limitingembodiment of a plot of mesh used to model transmitting and receivehorns and connecting wire in accordance with various aspects describedherein.

FIG. 7I is a graphical diagram illustrating, an example, non-limitingembodiment of a radial field intensity versus distance for threeexcitation frequencies. The light-yellow lines at the beginning and endof the calculation are the surface position of the horns in accordancewith various aspects described herein.

FIG. 7J is a graphical diagram illustrating, an example, non-limitingembodiment of plots for wire transmission calculations. (a) Power flowalong the wire for smooth and six strand wire case. (b) Mesh used tomodel six strand wire. (c) Magnitude of transverse electric field at 500cm in accordance with various aspects described herein.

FIG. 7K is a graphical diagram illustrating, an example, non-limitingembodiment of loss as a function of frequency calculated with theEigenmode solver for the Sommerfeld TM₀ mode with a radius of 0.5 cm onaluminum wire with a 0.1 mm water film thickness in accordance withvarious aspects described herein.

FIG. 7L is a graphical diagram illustrating, an example, non-limitingembodiment of (a) analytical fields for an m=1 Bessel-Gauss beam with nowire compared to the (b) numerical Bessel-Gauss-like TM₁ mode for 25 GHzwith a 5 mm radius wire and no water, and (c) E-field magnitude on twolineouts for the analytical and numerical result in accordance withvarious aspects described herein.

FIG. 7M is a graphical diagram illustrating, an example, non-limitingembodiment of field distributions for the Bessel-Gauss-like TM1 with a0.1 mm water layer showing the (a) magnitude and (b) vector plot of theelectric field, and the (c) magnitude and (d) vector plot of theelectric field in accordance with various aspects described herein.

FIG. 7N is a graphical diagram illustrating, an example, non-limitingembodiment of views showing the simulation volume and boundaryconditions required for periodic excitation. (a) Master/Slave boundaryhighlighted for the main simulation volume. (b) Master/Slave boundaryhighlighted for the PML volume. (c) Perfect H boundary highlighted. (d)Magnitude of the electric field plotted for the TM₁ mode at 25 GHz witha 0.1 mm water layer in accordance with various aspects describedherein.

FIG. 7O is a graphical diagram illustrating, an example, non-limitingembodiment of electric field distribution from an exemplary S3Psimulation for the TM₁ mode. The lack of intensity fringes along thez-direction in the XZ plane indicates a very low reflection coefficientat the boundaries. Note the nearly identical field distribution at theinput and output XY plans in accordance with various aspects describedherein.

FIG. 7P1A is a graphical diagram illustrating, an example, non-limitingembodiment of (a) target field (b) Initial field distribution of theTE11 mode at the entrance aperture of (c) the horn, and (d) the outputfield profile of the horn which has mode converted and is closer to theinitial target field.

FIG. 7P1B is a graphical diagram illustrating, an example, non-limitingembodiment of a tapered dielectric coating on a transmission medium.

FIG. 7P1C are graphical diagrams illustrating, an example, non-limitingembodiments of horn geometries.

FIGS. 7P1D and 7P1E are graphical diagrams illustrating, example,non-limiting embodiments of simulated performance of a horn structure asdepicted in FIG. 7P1C at 5 GHz and 12.5 GHz, respectively.

FIG. 7P1F is a graphical diagram illustrating, an example, non-limitingembodiment of a horn.

FIG. 7P2 is a graphical diagram illustrating, an example, non-limitingembodiment of a desired beam structure of an electromagnetic wave inaccordance with various aspects described herein.

FIG. 7P3 is a graphical diagram illustrating, an example, non-limitingembodiment of a front-view of an aperture of a coupler in accordancewith various aspects described herein.

FIG. 7P4 is a graphical diagram illustrating, an example, non-limitingembodiment of a side-view of the aperture of the coupler of FIG. 7P3 inaccordance with various aspects described herein.

FIG. 7P5 illustrates a flow diagram of an example, non-limitingembodiment of a method in accordance with various aspects describedherein.

FIG. 7Q is a graphical diagram illustrating, an example, non-limitingembodiment of simulation in T3P for a Bessel-Gauss TM₁ excitation withno wire demonstrating divergence over 3 m for a 10 GHz bandwidth, 1 nspulse. (a) Electric field distribution for five progressive times duringthe simulation. (b) Analytical fields compared with (c) numerical resultfor five distances. The transverse radius of the simulation domain was0.5 m in accordance with various aspects described herein.

FIG. 7R is a graphical diagram illustrating, an example, non-limitingembodiment of (a) Magnitude of the electric field on the XY plane at19.2 m for a 25 GHz, r=0.5 cm wire, t=0.1 mm water film, TM₁ modesimulation with T3P. (b) Comparison between the electric field profilefor y=0 between the input field distribution (blue) and the output (red)in accordance with various aspects described herein.

FIG. 7S is a graphical diagram illustrating, an example, non-limitingembodiment located on the left of a power density plot on the XY planeat 19.2 m for a 25 GHz, r=0.5 cm wire, t=0.1 mm water film, TM₁ modesimulation in T3P with red arrows showing the local Poynting vector(ExH) in accordance with various aspects described herein.

FIG. 7T is a graphical diagram illustrating, an example, non-limitingembodiment of an integrated Poynting vector (red) compared to a wireaxis (blue) at 19.2 m for a 25 GHz, r=0.5 cm wire, t=0.1 mm water film,TM₁ mode simulation in accordance with various aspects described herein.

FIG. 7U is a graphical diagram illustrating, an example, non-limitingembodiment of a comparison between (a) the magnitude of the electricfield in the presence of a 0.1 mm water film for the Bessel-Gauss TM₁ at20 GHz, (b) TM₁₁ mode at 65 GHz and (c) TM₁₁ mode at 25 GHz with a 2 mminsulator in accordance with various aspects described herein.

FIG. 7V is a graphical diagram illustrating, an example, non-limitingembodiment of loss as a function of frequency for the Bessel-Gauss-likeTM₁ and TM₁₁ mode with a 0.1 mm water coating on a 0.5 cm radiusaluminum wire in accordance with various aspects described herein.

FIG. 7W is a graphical diagram illustrating, an example, non-limitingembodiment of loss as a function of water thickness for theBessel-Gauss-like TM₁ mode at 57 GHz vs. water coating thickness on a0.5 cm radius aluminum wire in accordance with various aspects describedherein.

FIG. 7X is a graphical diagram illustrating, an example, non-limitingembodiment of loss as a function of frequency for the Bessel-Gauss-likeTM₁₁ mode with a 2 mm insulator layer 0.1 mm water coating on a 0.5 cmradius aluminum wire. Dielectric constants given in Table 7 inaccordance with various aspects described herein.

FIG. 7Y is a graphical diagram illustrating, an example, non-limitingembodiment of a 25 m simulation of the TM1 mode at 12.5 GHz with showingthe (a) mesh, (b) a snap shot in time of the pulse electric fieldmagnitude and (c) a zoomed in view of the pulse in accordance withvarious aspects described herein.

FIG. 7Z is a graphical diagram illustrating, an example, non-limitingembodiment of a comparison between two simulations at 12.5 GHz (a) withwater droplets, (b) without water droplets with no observable differencein attenuation of the TM₁, and (c) water droplets on wire highlightedand appearing as colored dots in accordance with various aspectsdescribed herein.

FIG. 7AA is a graphical diagram illustrating, an example, non-limitingembodiment of (a) spectral amplitude compared between input (blue) andout (red) pulse for a 1 ns 12.5 GHz TM₁ pulse for at 25 m simulation ona 0.5 cm radius wire with 0.1 mm water film. (b) Calculated loss fromspectral attenuation for various simulations of the TM₁ mode inaccordance with various aspects described herein.

FIG. 7AB is a graphical diagram illustrating, an example, non-limitingembodiment of dispersion as a function of frequency calculated from a 25GHz TM₁ pulse in a 10 m simulation on a 0.5 cm radius wire with a 01. mmwater film after removing the constant phase advance from the groupvelocity of the pulse in accordance with various aspects describedherein.

FIG. 8 is a block diagram illustrating an example, non-limitingembodiment of a communications network in accordance with variousaspects described herein.

FIG. 9 is a block diagram illustrating an example, non-limitingembodiment of a virtualized communication network in accordance withvarious aspects described herein.

FIG. 10 is a block diagram of an example, non-limiting embodiment of acomputing environment in accordance with various aspects describedherein.

FIG. 11 is a block diagram of an example, non-limiting embodiment of amobile network platform in accordance with various aspects describedherein.

FIG. 12 is a block diagram of an example, non-limiting embodiment of acommunication device in accordance with various aspects describedherein.

DETAILED DESCRIPTION

One or more embodiments are now described with reference to thedrawings, wherein like reference numerals are used to refer to likeelements throughout the drawings. In the following description, forpurposes of explanation, numerous details are set forth in order toprovide a thorough understanding of the various embodiments. It isevident, however, that the various embodiments can be practiced withoutthese details (and without applying to any particular networkedenvironment or standard).

In an embodiment, a guided wave communication system is presented forsending and receiving communication signals such as data or othersignaling via guided electromagnetic waves. The guided electromagneticwaves include, for example, surface waves or other electromagnetic wavesthat are bound to or guided by a transmission medium as describedherein. It will be appreciated that a variety of transmission media canbe utilized with guided wave communications without departing fromexample embodiments. Examples of such transmission media can include oneor more of the following, either alone or in one or more combinations:wires, whether insulated or not, and whether single-stranded ormulti-stranded; conductors of other shapes or configurations includingunshielded twisted pair cables including single twisted pairs, Category5e and other twisted pair cable bundles, other wire bundles, cables,rods, rails, pipes; non-conductors such as dielectric pipes, rods,rails, or other dielectric members; combinations of conductors anddielectric materials such as coaxial cables; or other guided wavetransmission media.

The inducement of guided electromagnetic waves that propagate along atransmission medium can be independent of any electrical potential,charge or current that is injected or otherwise transmitted through thetransmission medium as part of an electrical circuit. For example, inthe case where the transmission medium is a wire, it is to beappreciated that while a small current in the wire may be formed inresponse to the propagation of the electromagnetic waves guided alongthe wire, this can be due to the propagation of the electromagnetic wavealong the wire surface, and is not formed in response to electricalpotential, charge or current that is injected into the wire as part ofan electrical circuit. The electromagnetic waves traveling along thewire therefore do not require an electrical circuit (i.e., ground orother electrical return path) to propagate along the wire surface. Thewire therefore can be a single wire transmission line that is not partof an electrical circuit. For example, electromagnetic waves canpropagate along a wire configured as an electrical open circuit. Also,in some embodiments, a wire is not necessary, and the electromagneticwaves can propagate along a single line transmission medium that is nota wire including a single line transmission medium that isconductorless. Accordingly, electromagnetic waves can propagate along aphysical transmission medium without requiring an electrical returnpath.

More generally, “guided electromagnetic waves” or “guided waves” asdescribed by the subject disclosure are affected by the presence of aphysical object that is at least a part of the transmission medium(e.g., a bare wire or other conductor, a dielectric including adielectric core without a conductive shield and/or without an innerconductor, an insulated wire, a conduit or other hollow element whetherconductive or not, a bundle of insulated wires that is coated, coveredor surrounded by a dielectric or insulator or other wire bundle, oranother form of solid, liquid or otherwise non-gaseous transmissionmedium) so as to be at least partially bound to or guided by thephysical object and so as to propagate along a transmission path of thephysical object. Such a physical object can operate as at least a partof a transmission medium that guides, by way of one or more interfacesof the transmission medium (e.g., an outer surface, inner surface, aninterstitial spacing formed between surfaces of a transmission medium,an interior portion between the outer and the inner surfaces or otherboundary between elements of the transmission medium).

In this fashion, a transmission medium may support multiple transmissionpaths over different surfaces of the transmission medium. For example, astranded cable or wire bundle may support electromagnetic waves that areguided by the outer surface of the stranded cable or wire bundle, aswell as electromagnetic waves that are guided by inner cable surfacesbetween two, three or more individual strands or wires within thestranded cable or wire bundle. For example, electromagnetic waves can beguided within interstitial areas of a stranded cable, insulated twistedpair wires, or a wire bundle. The guided electromagnetic waves of thesubject disclosure are launched from a sending (transmitting) device andpropagate along the transmission medium for reception by at least onereceiving device. The propagation of guided electromagnetic waves, cancarry energy, data and/or other signals along the transmission path fromthe sending device to the receiving device.

As used herein the term “conductor” (based on a definition of the term“conductor” from IEEE 100, the Authoritative Dictionary of IEEEStandards Terms, 7^(th) Edition, 2000) means a substance or body thatallows a current of electricity to pass continuously along it. The terms“insulator”, “conductorless” or “nonconductor” (based on a definition ofthe term “insulator” from IEEE 100, the Authoritative Dictionary of IEEEStandards Terms, 7^(th) Edition, 2000) means a device or material inwhich electrons or ions cannot be moved easily. It is possible for aninsulator, or a conductorless or nonconductive material to be intermixedintentionally (e.g., doped) or unintentionally into a resultingsubstance with a small amount of another material having the propertiesof a conductor. However, the resulting substance may remainsubstantially resistant to a flow of a continuous electrical currentalong the resulting substance. Furthermore, a conductorless member suchas a dielectric rod or other conductorless core lacks an inner conductorand a conductive shield.

As used herein, the term “eddy current” (based on a definition of theterm “conductor” from IEEE 100, the Authoritative Dictionary of IEEEStandards Terms, 7^(th) Edition, 2000) means a current that circulatesin a metallic material as a result of electromotive forces induced by avariation of magnetic flux. Although it may be possible for aninsulator, conductorless or nonconductive material in the foregoingembodiments to allow eddy currents that circulate within the doped orintermixed conductor and/or a very small continuous flow of anelectrical current along the extent of the insulator, conductorless ornonconductive material, any such continuous flow of electrical currentalong such an insulator, conductorless or nonconductive material is deminimis compared to the flow of an electrical current along a conductor.Accordingly, in the subject disclosure an insulator, and a conductorlessor nonconductor material are not considered to be a conductor. The term“dielectric” means an insulator that can be polarized by an appliedelectric field. When a dielectric is placed in an electric field,electric charges do not continuously flow through the material as theydo in a conductor, but only slightly shift from their averageequilibrium positions causing dielectric polarization. The terms“conductorless transmission medium or non-conductor transmission medium”can mean a transmission medium consisting of any material (orcombination of materials) that may or may not contain one or moreconductive elements but lacks a continuous conductor between the sendingand receiving devices along the conductorless transmission medium ornon-conductor transmission medium—similar or identical to theaforementioned properties of an insulator, conductorless ornonconductive material.

Unlike free space propagation of wireless signals such as unguided (orunbounded) electromagnetic waves that decrease in intensity inversely bythe square of the distance traveled by the unguided electromagneticwaves, guided electromagnetic waves can propagate along a transmissionmedium with less loss in magnitude per unit distance than experienced byunguided electromagnetic waves.

Unlike electrical signals, guided electromagnetic waves can propagatealong different types of transmission media from a sending device to areceiving device without requiring a separate electrical return pathbetween the sending device and the receiving device. As a consequence,guided electromagnetic waves can propagate from a sending device to areceiving device along a conductorless transmission medium including atransmission medium having no conductive components (e.g., a dielectricstrip, rod, or pipe), or via a transmission medium having no more than asingle conductor (e.g., a single bare wire or insulated wire configuredin an open electrical circuit). Even if a transmission medium includesone or more conductive components and the guided electromagnetic wavespropagating along the transmission medium generate currents that flow inthe one or more conductive components in a direction of the guidedelectromagnetic waves, such guided electromagnetic waves can propagatealong the transmission medium from a sending device to a receivingdevice without requiring a flow of opposing currents on an electricalreturn path between the sending device and the receiving device (i.e.,in an electrical open circuit configuration).

In a non-limiting illustration, consider electrical systems thattransmit and receive electrical signals between sending and receivingdevices by way of conductive media. Such systems generally rely on anelectrical forward path and an electrical return path. For instance,consider a coaxial cable having a center conductor and a ground shieldthat are separated by an insulator. Typically, in an electrical system afirst terminal of a sending (or receiving) device can be connected tothe center conductor, and a second terminal of the sending (orreceiving) device can be connected to the ground shield or other secondconductor. If the sending device injects an electrical signal in thecenter conductor via the first terminal, the electrical signal willpropagate along the center conductor causing forward currents in thecenter conductor, and return currents in the ground shield or othersecond conductor. The same conditions apply for a two terminal receivingdevice.

In contrast, consider a guided wave communication system such asdescribed in the subject disclosure, which can utilize differentembodiments of a transmission medium (including among others a coaxialcable) for transmitting and receiving guided electromagnetic waveswithout requiring an electrical return path. In one embodiment, forexample, the guided wave communication system of the subject disclosurecan be configured to induce guided electromagnetic waves that propagatealong an outer surface of a coaxial cable. Although the guidedelectromagnetic waves can cause forward currents on the ground shield,the guided electromagnetic waves do not require return currents on, forexample, the center conductor to enable the guided electromagnetic wavesto propagate along the outer surface of the coaxial cable. The same canbe said of other transmission media used by a guided wave communicationsystem for the transmission and reception of guided electromagneticwaves. For example, guided electromagnetic waves induced by the guidedwave communication system on a bare wire, an insulated wire, or adielectric transmission medium (e.g., a dielectric core with noconductive materials), can propagate along the bare wire, the insulatedbare wire, or the dielectric transmission medium without requiringreturn currents on an electrical return path.

Consequently, electrical systems that require forward and returnconductors for carrying corresponding forward and reverse currents onconductors to enable the propagation of electrical signals injected by asending device are distinct from guided wave systems that induce guidedelectromagnetic waves on an interface of a transmission medium withoutrequiring an electrical return path to enable the propagation of theguided electromagnetic waves along the interface of the transmissionmedium. It is also noted that a transmission medium having an electricalreturn path (e.g., ground) for purposes of conducting currents (e.g., apower line) can be used to contemporaneously propagate guidedelectromagnetic waves along the transmission medium. However, thepropagation of the guided electromagnetic waves is not dependent on theelectrical currents flowing through the transmission medium. Forexample, if the electrical currents flowing through the transmissionmedium stop flowing for any reason (e.g., a power outage), guidedelectromagnetic waves propagating along the transmission medium cancontinue to propagate without interruption.

It is further noted that guided electromagnetic waves as described inthe subject disclosure can have an electromagnetic field structure thatlies primarily or substantially on an outer surface of a transmissionmedium so as to be bound to or guided by the outer surface of thetransmission medium and so as to propagate non-trivial distances on oralong the outer surface of the transmission medium. In otherembodiments, guided electromagnetic waves can have an electromagneticfield structure that substantially lies above an outer surface of atransmission medium, but is nonetheless bound to or guided by thetransmission medium and so as to propagate non-trivial distances on oralong the transmission medium. In other embodiments, guidedelectromagnetic waves can have an electromagnetic field structure thathas a field strength that is de minimis at the outer surface, below theouter surface, and/or in proximity to the outer surface of atransmission medium, but is nonetheless bound to or guided by thetransmission medium and so as to propagate non-trivial distances alongthe transmission medium.

In other embodiments, guided electromagnetic waves can have anelectromagnetic field structure that lies primarily or substantiallybelow an outer surface of a transmission medium so as to be bound to orguided by an inner material of the transmission medium (e.g., dielectricmaterial) and so as to propagate non-trivial distances within the innermaterial of the transmission medium. In other embodiments, guidedelectromagnetic waves can have an electromagnetic field structure thatlies within a region that is partially below and partially above anouter surface of a transmission medium so as to be bound to or guided bythis region of the transmission medium and so as to propagatenon-trivial distances along this region of the transmission medium. Itwill be appreciated that electromagnetic waves that propagate along atransmission medium or are otherwise guided by a transmission medium(i.e., guided electromagnetic waves) can have an electric fieldstructure such as described in one or more of the foregoing embodiments.The desired electromagnetic field structure in an embodiment may varybased upon a variety of factors, including the desired transmissiondistance, the characteristics of the transmission medium itself,environmental conditions/characteristics outside of the transmissionmedium (e.g., presence of rain, fog, humidity, atmospheric conditions,etc.), and characteristics of an electromagnetic wave that areconfigurable by a launcher (or coupler) as will be described below(e.g., configurable wave mode, configurable electromagnetic fieldstructure, configurable polarity, configurable wavelength, configurablebandwidth, and so on).

Various embodiments described herein relate to coupling devices, thatcan be referred to as “waveguide coupling devices”, “waveguide couplers”or more simply as “couplers”, “coupling devices” or “launchers” forlaunching/inducing and/or receiving/extracting guided electromagneticwaves to and from a transmission medium. A wavelength of the guidedelectromagnetic waves can be small compared to one or more dimensions ofthe coupling device and/or the transmission medium such as thecircumference of a wire or other cross sectional dimension. Suchelectromagnetic waves can operate at millimeter wave frequencies (e.g.,30 to 300 GHz), or lower than microwave frequencies such as 300 MHz to30 GHz. Electromagnetic waves can be induced to propagate along atransmission medium by a coupling device, such as: a strip, arc or otherlength of dielectric material; a millimeter wave integrated circuit(MMIC), a horn, monopole, dipole, rod, slot, patch, planar or otherantenna; an array of antennas; a magnetic resonant cavity or otherresonant coupler; a coil, a strip line, a coaxial waveguide, a hollowwaveguide, or other waveguide and/or other coupling device.

In operation, the coupling device receives an electromagnetic wave froma transmitter or transmission medium. The electromagnetic fieldstructure of the electromagnetic wave can be carried below an outersurface of the coupling device, substantially on the outer surface ofthe coupling device, within a hollow cavity of the coupling device, canbe radiated from a coupling device or a combination thereof. When thecoupling device is in close proximity to a transmission medium, at leasta portion of an electromagnetic wave can couple from the coupling deviceto the transmission medium, and continues to propagate as guidedelectromagnetic waves along the transmission medium. In a reciprocalfashion, a coupling device can receive or extract at least a portion ofa guided electromagnetic waves propagating along a transmission mediumand transfer these electromagnetic waves to a receiver. The guidedelectromagnetic waves launched and/or received by the coupling devicepropagate along the transmission medium from a sending device to areceiving device without requiring an electrical return path between thesending device and the receiving device. In this circumstance, thetransmission medium acts as a waveguide to support the propagation ofthe guided electromagnetic waves from the sending device to thereceiving device.

According to an example embodiment, a surface wave is a type of guidedwave that is guided by a surface of a transmission medium, such as anexterior or outer surface or an interior or inner surface including aninterstitial surface of the transmission medium such as the interstitialarea between wires in a multi-stranded cable, insulated twisted pairwires, or wire bundle, and/or another surface of the transmission mediumthat is adjacent to or exposed to another type of medium havingdifferent properties (e.g., dielectric properties). Indeed, in anexample embodiment, a surface of the transmission medium that guides asurface wave can represent a transitional surface between two differenttypes of media. For example, in the case of a bare wire, the surface ofthe wire can be the outer or exterior conductive surface of the barewire or uninsulated wire that is exposed to air or free space.

As another example, in the case of insulated wire, the surface of thewire can be the conductive portion of the wire, an exterior surface ofthe insulation of the wire, an inner region of the insulation of thewire, a gap formed between the insulation and the conductor of the wire,or a combination thereof. Accordingly, a surface of the transmissionmedium can be any one of an inner surface of an insulator surface of awire or a conductive surface of the wire that is separated by a gapcomposed of, for example, air or free space. A surface of a transmissionmedium can otherwise be any material region of the transmission medium.The surface that guides an electromagnetic wave can depend upon therelative differences in the properties (e.g., dielectric properties) ofthe insulator, air, and/or the conductor and further dependent on thefrequency and propagation mode or modes of the guided wave.

According to an example embodiment, the term “about” a wire or othertransmission medium used in conjunction with a guided wave can includefundamental guided wave propagation modes such as a guided wave having acircular or substantially circular field pattern/distribution, asymmetrical electromagnetic field pattern/distribution (e.g., electricfield or magnetic field) or other fundamental mode pattern at leastpartially around a wire or other transmission medium. Unlike Zenneckwaves that propagate along a single planar surface of a planartransmission medium, the guided electromagnetic waves of the subjectdisclosure that are bound to a transmission medium can haveelectromagnetic field patterns that surround or circumscribe, at leastin part, a non-planar surface of the transmission medium withelectromagnetic energy in all directions, or in all but a finite numberof azimuthal null directions characterized by field strengths thatapproach zero field strength for infinitesimally small azimuthal widths.

For example, such non-circular field distributions can be unilateral ormulti-lateral with one or more axial lobes characterized by relativelyhigher field strength and/or one or more nulls directions of zero fieldstrength or substantially zero-field strength or null regionscharacterized by relatively low-field strength, zero-field strengthand/or substantially zero-field strength. Further, the fielddistribution can otherwise vary as a function of azimuthal orientationaround a transmission medium such that one or more angular regionsaround the transmission medium have an electric or magnetic fieldstrength (or combination thereof) that is higher than one or more otherangular regions of azimuthal orientation, according to an exampleembodiment. It will be appreciated that the relative orientations orpositions of the guided wave higher order modes, particularlyasymmetrical modes, can vary as the guided wave travels along the wire.

In addition, when a guided wave propagates “about” a wire or other typeof transmission medium, it can do so according to a guided wavepropagation mode that includes not only the fundamental wave propagationmodes (e.g., zero order modes), but additionally or alternatively,non-fundamental wave propagation modes such as higher-order guided wavemodes (e.g., 1^(st) order modes, 2^(nd) order modes, etc.). Higher-ordermodes include symmetrical modes that have a circular or substantiallycircular electric or magnetic field distribution and/or a symmetricalelectric or magnetic field distribution, or asymmetrical modes and/orother guided (e.g., surface) waves that have non-circular and/orasymmetrical field distributions around the wire or other transmissionmedium. For example, the guided electromagnetic waves of the subjectdisclosure can propagate along a transmission medium from the sendingdevice to the receiving device or along a coupling device via one ormore guided wave modes such as a fundamental transverse magnetic (TM)TM00 mode (or Goubau mode), a fundamental hybrid mode (EH or HE) “EH00”mode or “HE00” mode, a transverse electromagnetic “TEMnm” mode, a totalinternal reflection (TIR) mode or any other mode such as EHnm, HEnm orTMnm, where n and/or m have integer values greater than or equal to 0,and other fundamental, hybrid and non-fundamental wave modes.

As used herein, the term “guided wave mode” refers to a guided wavepropagation mode of a transmission medium, coupling device or othersystem component of a guided wave communication system that propagatesfor non-trivial distances along the length of the transmission medium,coupling device or other system component.

As used herein, the term “millimeter-wave” can refer to electromagneticwaves/signals that fall within the “millimeter-wave frequency band” of30 GHz to 300 GHz. The term “microwave” can refer to electromagneticwaves/signals that fall within a “microwave frequency band” of 300 MHzto 300 GHz. The term “radio frequency” or “RF” can refer toelectromagnetic waves/signals that fall within the “radio frequencyband” of 10 kHz to 1 THz. It is appreciated that wireless signals,electrical signals, and guided electromagnetic waves as described in thesubject disclosure can be configured to operate at any desirablefrequency range, such as, for example, at frequencies within, above orbelow millimeter-wave and/or microwave frequency bands. In particular,when a coupling device or transmission medium includes a conductiveelement, the frequency of the guided electromagnetic waves that arecarried by the coupling device and/or propagate along the transmissionmedium can be below the mean collision frequency of the electrons in theconductive element. Further, the frequency of the guided electromagneticwaves that are carried by the coupling device and/or propagate along thetransmission medium can be a non-optical frequency, e.g., a radiofrequency below the range of optical frequencies that begins at 1 THz.

It is further appreciated that a transmission medium as described in thesubject disclosure can be configured to be opaque or otherwise resistantto (or at least substantially reduce) a propagation of electromagneticwaves operating at optical frequencies (e.g., greater than 1 THz).

As used herein, the term “antenna” can refer to a device that is part ofa transmitting or receiving system to transmit/radiate or receive freespace wireless signals.

In accordance with one or more embodiments, a method can includegenerating, by a transmitter, a signal, and inducing, by a coupler, anelectromagnetic wave that propagates along a physical transmissionmedium, wherein the coupler has a structure that converts the signalinto a plurality of wave modes that combine to form the electromagneticwave, and wherein the electromagnetic wave has an electromagnetic fieldconfiguration that reduces leakage of the electromagnetic wave as theelectromagnetic wave propagates along the physical transmission medium.

In accordance with one or more embodiments, a machine-readable mediumcan include executable instructions that, when executed by a processingsystem including a processor, facilitate performance of operations. Theoperations can include receiving data, and causing a transmitter totransmit a signal that conveys the data, wherein a coupler coupled tothe transmitter converts the signal into a plurality of wave modes thatcombine to form a first electromagnetic wave that propagates along atransmission medium, wherein the first electromagnetic wave has a depthof focus that increases a concentration of electromagnetic fields of thefirst electromagnetic wave, and wherein the concentration ofelectromagnetic fields reduces a leakage of the first electromagneticwave while propagating along the transmission medium.

In accordance with one or more embodiments, a communication device caninclude a processing system including a processor, and a memory thatstores executable instructions that, when executed by the processingsystem, facilitate performance of operations. The operations can includedetecting an obstruction that increases a propagation loss of a firstelectromagnetic wave as it propagates along a physical transmissionmedium, and responsive to the detecting, inducing propagation of asecond electromagnetic wave along the physical transmission medium,wherein the second electromagnetic wave comprises an electromagneticfield configuration, wherein a first portion of the electromagneticfield configuration has a first intensity, wherein a second portion ofthe electromagnetic field configuration has a second intensity, whereinthe first intensity of the first portion of the electromagnetic fieldconfiguration is greater than the second intensity of the second portionof the electromagnetic field configuration, and wherein the firstportion of the electromagnetic field configuration is positioned awayfrom the obstruction to reduce the propagation loss caused by theobstruction.

Referring now to FIG. 1, a block diagram 100 illustrating an example,non-limiting embodiment of a guided wave communications system is shown.In operation, a transmission device 101 receives one or morecommunication signals 110 from a communication network or othercommunications device that includes data and generates guided waves 120to convey the data via the transmission medium 125 to the transmissiondevice 102. The transmission device 102 receives the guided waves 120and converts them to communication signals 112 that include the data fortransmission to a communications network or other communications device.The guided waves 120 can be modulated to convey data via a modulationtechnique such as phase shift keying, frequency shift keying, quadratureamplitude modulation, amplitude modulation, multi-carrier modulationsuch as orthogonal frequency division multiplexing and via multipleaccess techniques such as frequency division multiplexing, time divisionmultiplexing, code division multiplexing, multiplexing via differingwave propagation modes and via other modulation and access strategies.

The communication network or networks can include a wirelesscommunication network such as a mobile data network, a cellular voiceand data network, a wireless local area network (e.g., WiFi or an IEEE802.xx network), a satellite communications network, a personal areanetwork or other wireless network. The communication network or networkscan also include a wired communication network such as a telephonenetwork, an Ethernet network, a local area network, a wide area networksuch as the Internet, a broadband access network, a cable network, afiber optic network, or other wired network. The communication devicescan include a network edge device, bridge device or home gateway, aset-top box, broadband modem, telephone adapter, access point, basestation, or other fixed communication device, a mobile communicationdevice such as an automotive gateway or automobile, laptop computer,tablet, smartphone, cellular telephone, or other communication device.

In an example embodiment, the guided wave communication system 100 canoperate in a bi-directional fashion where transmission device 102receives one or more communication signals 112 from a communicationnetwork or device that includes other data and generates guided waves122 to convey the other data via the transmission medium 125 to thetransmission device 101. In this mode of operation, the transmissiondevice 101 receives the guided waves 122 and converts them tocommunication signals 110 that include the other data for transmissionto a communications network or device. The guided waves 122 can bemodulated to convey data via a modulation technique such as phase shiftkeying, frequency shift keying, quadrature amplitude modulation,amplitude modulation, multi-carrier modulation such as orthogonalfrequency division multiplexing and via multiple access techniques suchas frequency division multiplexing, time division multiplexing, codedivision multiplexing, multiplexing via differing wave propagation modesand via other modulation and access strategies.

The transmission medium 125 can include a cable having at least oneinner portion surrounded by a dielectric material such as an insulatoror other dielectric cover, coating or other dielectric material, thedielectric material having an outer surface and a correspondingcircumference. In an example embodiment, the transmission medium 125operates as a single-wire transmission line to guide the transmission ofan electromagnetic wave. When the transmission medium 125 is implementedas a single wire transmission system, it can include a wire. The wirecan be insulated or uninsulated, and single-stranded or multi-stranded(e.g., braided). In other embodiments, the transmission medium 125 cancontain conductors of other shapes or configurations including wirebundles, cables, rods, rails, pipes. In addition, the transmissionmedium 125 can include non-conductors such as dielectric pipes, rods,rails, or other dielectric members; combinations of conductors anddielectric materials, conductors without dielectric materials or otherguided wave transmission media and/or consist essentially ofnon-conductors such as dielectric pipes, rods, rails, or otherdielectric members that operate without a continuous conductor such asan inner conductor or a conductive shield. It should be noted that thetransmission medium 125 can otherwise include any of the transmissionmedia previously discussed.

Further, as previously discussed, the guided waves 120 and 122 can becontrasted with radio transmissions over free space/air or conventionalpropagation of electrical power or signals through the conductor of awire via an electrical circuit. In addition to the propagation of guidedwaves 120 and 122, the transmission medium 125 may optionally containone or more wires that propagate electrical power or other communicationsignals in a conventional manner as a part of one or more electricalcircuits.

Referring now to FIG. 2, a block diagram 200 illustrating an example,non-limiting embodiment of a transmission device is shown. Thetransmission device 101 or 102 includes a communications interface (I/F)205, a transceiver 210 and a coupler 220.

In an example of operation, the communications interface 205 receives acommunication signal 110 or 112 that includes data. In variousembodiments, the communications interface 205 can include a wirelessinterface for receiving a wireless communication signal in accordancewith a wireless standard protocol such as LTE or other cellular voiceand data protocol, WiFi or an 802.11 protocol, WIMAX protocol, UltraWideband protocol, Bluetooth® protocol, Zigbee® protocol, a directbroadcast satellite (DBS) or other satellite communication protocol orother wireless protocol. In addition or in the alternative, thecommunications interface 205 includes a wired interface that operates inaccordance with an Ethernet protocol, universal serial bus (USB)protocol, a data over cable service interface specification (DOCSIS)protocol, a digital subscriber line (DSL) protocol, a Firewire (IEEE1394) protocol, or other wired protocol. In additional tostandards-based protocols, the communications interface 205 can operatein conjunction with other wired or wireless protocol. In addition, thecommunications interface 205 can optionally operate in conjunction witha protocol stack that includes multiple protocol layers including a MACprotocol, transport protocol, application protocol, etc.

In an example of operation, the transceiver 210 generates anelectromagnetic wave based on the communication signal 110 or 112 toconvey the data. The electromagnetic wave has at least one carrierfrequency and at least one corresponding wavelength. The carrierfrequency can be within a millimeter-wave frequency band of 30 GHz-300GHz, such as 60 GHz or a carrier frequency in the range of 30-40 GHz ora lower frequency band of 300 MHz-30 GHz in the microwave frequencyrange such as 26-30 GHz, 11 GHz, or 3-6 GHz, but it will be appreciatedthat other carrier frequencies are possible in other embodiments. In onemode of operation, the transceiver 210 merely upconverts thecommunications signal or signals 110 or 112 for transmission of theelectromagnetic signal in the microwave or millimeter-wave band as aguided electromagnetic wave that is guided by or bound to thetransmission medium 125. In another mode of operation, thecommunications interface 205 either converts the communication signal110 or 112 to a baseband or near baseband signal or extracts the datafrom the communication signal 110 or 112 and the transceiver 210modulates a high-frequency carrier with the data, the baseband or nearbaseband signal for transmission. It should be appreciated that thetransceiver 210 can modulate the data received via the communicationsignal 110 or 112 to preserve one or more data communication protocolsof the communication signal 110 or 112 either by encapsulation in thepayload of a different protocol or by simple frequency shifting. In thealternative, the transceiver 210 can otherwise translate the datareceived via the communication signal 110 or 112 to a protocol that isdifferent from the data communication protocol or protocols of thecommunication signal 110 or 112.

In an example of operation, the coupler 220 couples the electromagneticwave to the transmission medium 125 as a guided electromagnetic wave toconvey the communications signal or signals 110 or 112. While the priordescription has focused on the operation of the transceiver 210 as atransmitter, the transceiver 210 can also operate to receiveelectromagnetic waves that convey other data from the single wiretransmission medium via the coupler 220 and to generate communicationssignals 110 or 112, via communications interface 205 that includes theother data. Consider embodiments where an additional guidedelectromagnetic wave conveys other data that also propagates along thetransmission medium 125. The coupler 220 can also couple this additionalelectromagnetic wave from the transmission medium 125 to the transceiver210 for reception.

The transmission device 101 or 102 includes an optional trainingcontroller 230. In an example embodiment, the training controller 230 isimplemented by a standalone processor or a processor that is shared withone or more other components of the transmission device 101 or 102. Thetraining controller 230 selects the carrier frequencies, modulationschemes and/or guided wave modes for the guided electromagnetic wavesbased on testing of the transmission medium 125, environmentalconditions and/or feedback data received by the transceiver 210 from atleast one remote transmission device coupled to receive the guidedelectromagnetic wave.

In an example embodiment, a guided electromagnetic wave transmitted by aremote transmission device 101 or 102 conveys data that also propagatesalong the transmission medium 125. The data from the remote transmissiondevice 101 or 102 can be generated to include the feedback data. Inoperation, the coupler 220 also couples the guided electromagnetic wavefrom the transmission medium 125 and the transceiver receives theelectromagnetic wave and processes the electromagnetic wave to extractthe feedback data.

In an example embodiment, the training controller 230 operates based onthe feedback data to evaluate a plurality of candidate frequencies,modulation schemes and/or transmission modes to select a carrierfrequency, modulation scheme and/or transmission mode to enhanceperformance, such as throughput, signal strength, reduce propagationloss, etc.

Consider the following example: a transmission device 101 beginsoperation under control of the training controller 230 by sending aplurality of guided waves as test signals such as pilot waves or othertest signals at a corresponding plurality of candidate frequenciesand/or candidate modes directed to a remote transmission device 102coupled to the transmission medium 125. The guided waves can include, inaddition or in the alternative, test data. The test data can indicatethe particular candidate frequency and/or guide-wave mode of the signal.In an embodiment, the training controller 230 at the remote transmissiondevice 102 receives the test signals and/or test data from any of theguided waves that were properly received and determines the bestcandidate frequency and/or guided wave mode, a set of acceptablecandidate frequencies and/or guided wave modes, or a rank ordering ofcandidate frequencies and/or guided wave modes. This selection ofcandidate frequenc(ies) or/and guided-mode(s) are generated by thetraining controller 230 based on one or more optimizing criteria such asreceived signal strength, bit error rate, packet error rate, signal tonoise ratio, propagation loss, etc. The training controller 230generates feedback data that indicates the selection of candidatefrequenc(ies) or/and guided wave mode(s) and sends the feedback data tothe transceiver 210 for transmission to the transmission device 101. Thetransmission device 101 and 102 can then communicate data with oneanother based on the selection of candidate frequenc(ies) or/and guidedwave mode(s).

In other embodiments, the guided electromagnetic waves that contain thetest signals and/or test data are reflected back, repeated back orotherwise looped back by the remote transmission device 102 to thetransmission device 101 for reception and analysis by the trainingcontroller 230 of the transmission device 101 that initiated thesewaves. For example, the transmission device 101 can send a signal to theremote transmission device 102 to initiate a test mode where a physicalreflector is switched on the line, a termination impedance is changed tocause reflections, a loop back mode is switched on to coupleelectromagnetic waves back to the source transmission device 102, and/ora repeater mode is enabled to amplify and retransmit the electromagneticwaves back to the source transmission device 102. The trainingcontroller 230 at the source transmission device 102 receives the testsignals and/or test data from any of the guided waves that were properlyreceived and determines selection of candidate frequenc(ies) or/andguided wave mode(s).

While the procedure above has been described in a start-up orinitialization mode of operation, each transmission device 101 or 102can send test signals, evaluate candidate frequencies or guided wavemodes via non-test conditions such as normal transmissions or otherwiseevaluate candidate frequencies or guided wave modes at other times orcontinuously as well. In an example embodiment, the communicationprotocol between the transmission devices 101 and 102 can include anon-request or periodic test mode where either full testing or morelimited testing of a subset of candidate frequencies and guided wavemodes are tested and evaluated. In other modes of operation, there-entry into such a test mode can be triggered by a degradation ofperformance due to a disturbance, weather conditions, etc. In an exampleembodiment, the receiver bandwidth of the transceiver 210 is eithersufficiently wide or swept to receive all candidate frequencies or canbe selectively adjusted by the training controller 230 to a trainingmode where the receiver bandwidth of the transceiver 210 is sufficientlywide or swept to receive all candidate frequencies.

Referring now to FIG. 3, a block diagram 300 illustrating an example,non-limiting embodiment of a guided wave communications system is shown.This diagram depicts an exemplary environment in which a guided wavecommunication system, such as the guided wave communication systempresented in conjunction with FIG. 1, can be used.

To provide network connectivity to additional base station devices, abackhaul network that links the communication cells (e.g., macrocellsand macrocells) to network devices of a core network is desirable.Similarly, to provide network connectivity to a distributed antennasystem, an extended communication system that links base station devicesand their distributed antennas is also desirable. A guided wavecommunication system 300 such as shown in FIG. 3 can be provided toenable alternative, increased or additional network connectivity and awaveguide coupling system can be provided to transmit and/or receiveguided wave (e.g., surface wave) communications on a transmission mediumsuch as a wire that operates as a single-wire transmission line (e.g., autility line), and that can be used as a waveguide and/or that otherwiseoperates to guide the transmission of an electromagnetic wave.

The guided wave communication system 300 can comprise a first instanceof a distribution system 350 that includes one or more base stationdevices (e.g., base station device 304) that are communicably coupled toa central office 301 and/or a macrocell site 302. Base station device304 can be connected by a wired (e.g., fiber and/or cable), or by awireless (e.g., microwave wireless) connection to the macrocell site 302and the central office 301. A second instance of the distribution system360 can be used to provide wireless voice and data services to mobiledevice 322 and to residential and/or commercial establishments 342(herein referred to as establishments 342). System 300 can haveadditional instances of the distribution systems 350 and 360 forproviding voice and/or data services to mobile devices 322-324 andestablishments 342 as shown in FIG. 3.

Macrocells such as macrocell site 302 can have dedicated connections toa mobile network and base station device 304 or can share and/orotherwise use another connection. Central office 301 can be used todistribute media content and/or provide internet service provider (ISP)services to mobile devices 322-324 and establishments 342. The centraloffice 301 can receive media content from a constellation of satellites330 (one of which is shown in FIG. 3) or other sources of content, anddistribute such content to mobile devices 322-324 and establishments 342via the first and second instances of the distribution system 350 and360. The central office 301 can also be communicatively coupled to theInternet 303 for providing internet data services to mobile devices322-324 and establishments 342.

Base station device 304 can be mounted on, or attached to, utility pole316. In other embodiments, base station device 304 can be neartransformers and/or other locations situated nearby a power line. Basestation device 304 can facilitate connectivity to a mobile network formobile devices 322 and 324. Antennas 312 and 314, mounted on or nearutility poles 318 and 320, respectively, can receive signals from basestation device 304 and transmit those signals to mobile devices 322 and324 over a much wider area than if the antennas 312 and 314 were locatedat or near base station device 304.

It is noted that FIG. 3 displays three utility poles, in each instanceof the distribution systems 350 and 360, with one base station device,for purposes of simplicity. In other embodiments, systems 350 and 360can be expanded with more base station devices, and more utility poleswith distributed antennas and/or tethered connections to establishments342 (as well as other establishments).

A transmission device 306, such as transmission device 101 or 102presented in conjunction with FIG. 1, can transmit a signal from basestation device 304 to antennas 312 and 314 via utility or power line(s)that connect the utility poles 316, 318, and 320. To transmit thesignal, transmission device 306 frequency shifts the signal (e.g., viafrequency mixing) from base station device 304 or otherwise converts thesignal from the base station device 304 to a microwave band signal andthe transmission device 306 launches a microwave band wave thatpropagates as a guided wave traveling along the utility line or otherwire as described in previous embodiments. At utility pole 318, anothertransmission device 308 receives the guided wave (and optionally canamplify it as needed or desired or operate as a repeater to receive itand regenerate it) and sends it forward as a guided wave on the utilityline or other wire. The transmission device 308 can also extract thesignal in whole or in part from the microwave band guided wave andfrequency shift it to its prior operating frequency, e.g., convert it toits original cellular band frequency (e.g., 1.9 GHz or other definedcellular frequency) or another cellular (or non-cellular) bandfrequency. An antenna 312 can wireless transmit the frequency-shiftedsignal to mobile device 322. The process can be repeated by transmissiondevice 310, antenna 314 and mobile device 324, as necessary ordesirable.

Transmissions from mobile devices 322 and 324 can also be received byantennas 312 and 314 respectively. The transmission devices 308 and 310can frequency shift the receive signal (e.g., convert the cellular bandsignals to microwave band) and transmit the signals as guided wave(e.g., surface wave or other electromagnetic wave) transmissions overthe power line(s) to base station device 304.

Media content received by the central office 301 can be supplied to thesecond instance of the distribution system 360 via the base stationdevice 304 for distribution to mobile devices 322 and establishments342. The transmission device 310 can be tethered to the establishments342 by one or more wired connections or a wireless interface. The one ormore wired connections may include without limitation, a power line, acoaxial cable, a fiber cable, a twisted pair cable, a guided wavetransmission medium or other suitable mediums for distribution of mediacontent and/or for providing internet services.

In an example embodiment, the wired connections from the transmissiondevice 310 can be communicatively coupled to one or more very high bitrate digital subscriber line (VDSL) modems located at one or morecorresponding service area interfaces (SAIs—not shown) or pedestals,each SAI or pedestal providing services to a portion of theestablishments 342. The VDSL modems can be used to selectivelydistribute media content and/or provide internet services to gateways(not shown) located in the establishments 342. The SAIs or pedestals canalso be communicatively coupled to the establishments 342 over a wiredmedium such as a power line, a coaxial cable, a fiber cable, a twistedpair cable, a guided wave transmission medium or other suitable mediums.In other example embodiments, the transmission device 310 can becommunicatively coupled directly to establishments 342 withoutintermediate interfaces such as the SAIs or pedestals.

In another example embodiment, system 300 can employ diversity paths,where two or more utility lines or other wires are strung between theutility poles 316, 318, and 320 (e.g., for example, two or more wiresbetween poles 316 and 320) and redundant transmissions from basestation/macrocell site 302 are transmitted as guided waves down thesurface of the utility lines or other wires. The utility lines or otherwires can be either insulated or uninsulated, and depending on theenvironmental conditions that cause transmission losses, the couplingdevices can selectively receive signals from one or more of theinsulated or uninsulated utility lines or other wires. The selection canbe based on measurements of the signal-to-noise ratio of the wires, orbased on determined weather/environmental conditions (e.g., moisturedetectors, weather forecasts, etc.). The use of diversity paths withsystem 300 can enable alternate routing capabilities, load balancing,increased load handling, concurrent bi-directional or synchronouscommunications, spread spectrum communications, etc. Multi-inputmulti-output (MIMO), SISO, SIMO, and/or MISO transmission and receptiontechniques can also be employed, in the alternative, or in combinationwith the foregoing embodiments, by the transmission devices 306, 308,and/or 310.

It is noted that the use of the transmission devices 306, 308, and 310in FIG. 3 are by way of example only, and that in other embodiments,other uses are possible. For instance, transmission devices can be usedin a backhaul communication system, providing network connectivity tobase station devices. Transmission devices 306, 308, and 310 can be usedin circumstances where it is desirable to transmit guided wavecommunications over a wire, whether insulated or not insulated.Transmission devices 306, 308, and 310 can be configured with couplingdevices that do not make contact or have limited physical and/orelectrical contact with the wires that may carry high voltages. Thetransmission devices 306, 308, and 310 can be located away from the wire(e.g., spaced apart from the wire) and/or located on the wire so long asit is not electrically in contact with the wire allowing for easy,and/or less complex installation.

It is further noted, that while a base station device 304 and macrocellsite 302 are illustrated in an embodiment, other network configurationsare likewise possible. For example, devices such as access points orother wireless gateways can be employed in a similar fashion to extendthe reach of other networks such as a wireless local area network, awireless personal area network or other wireless network that operatesin accordance with a communication protocol such as a 802.11 protocol,WIMAX protocol, UltraWideband protocol, Bluetooth® protocol, Zigbee®protocol or other wireless protocol.

Turning now to FIG. 4, illustrated is a block diagram 400 illustratingan example, non-limiting embodiment of a bidirectional repeater system.In particular, a bidirectional repeater system is presented for use in atransmission device, such as transmission device 101 or 102 presented inconjunction with FIGS. 1, 2 and 3. The bidirectional repeater systemincludes waveguide coupling devices 402 and 404 that receive guide wavesfrom other coupling devices located in a distributed antenna system orbackhaul system, and/or transmit guided waves directed to couplingdevices located in the distributed antenna system or backhaul system.

In various embodiments, waveguide coupling device 402 can receive atransmission from another waveguide coupling device, wherein thetransmission has a plurality of subcarriers (or data channels). Diplexer406 can separate the transmission from other transmissions, and directthe transmission to a low-noise amplifier (“LNA”) 408. A frequency mixer428, coupled to a local oscillator 412, can frequency shift thetransmission (e.g., in the millimeter-wave band or around 38 GHz in someembodiments) to another frequency, such as a cellular band (˜1.9 GHz)for a distributed antenna system, a native frequency, or other frequencyfor a backhaul system. An extractor (or demultiplexer) 432 can extractfrom the frequency-shifted signal a subcarrier (or data channel) anddirect the extracted subcarrier (or data channel) to an output component422 for optional amplification, buffering or isolation by poweramplifier 424 for coupling to a communications interface 205 (such asshown in FIG. 2). The communications interface 205 can further processthe extracted subcarrier (or data channel) received from the poweramplifier 424 or otherwise transmit the extracted subcarrier over awireless or wired interface to other devices such as a base station,mobile devices, a building, etc. For the subcarriers that are not beingextracted at this location, extractor 432 can redirect them to anotherfrequency mixer 436, coupled to another local oscillator 414, that canfrequency-shift them to another carrier frequency (e.g., millimeter-waveband). The frequency-shifted signal can be directed to a power amplifier(“PA”) 416 and is then retransmitted by waveguide coupling device 404 toanother system, via diplexer 420.

An LNA 426 can be used to amplify, buffer or isolate signals that arereceived by the communication interface 205 and send the receivedsignals to a multiplexer 434 which merges the received signals withsignals that have been received from waveguide coupling device 404. Thesignals received from coupling device 404 have been split by diplexer420, and then passed through LNA 418, and frequency-shifted by frequencymixer 438. When the signals from the LNA 418 are combined by multiplexer434 with the signals provided by the LNA 426, they are frequency shiftedby frequency mixer 430, and then boosted by PA 410, and transmitted toanother system by waveguide coupling device 402 via duplexer 406. In anembodiment bidirectional repeater system can be merely a repeaterwithout the input/output device 422. In this embodiment, the multiplexer434 would not be utilized and signals from LNA 418 would be directed tomixer 430 as previously described. It will be appreciated that in someembodiments, the bidirectional repeater system could also be implementedusing two distinct and separate unidirectional repeaters. In analternative embodiment, a bidirectional repeater system could also be abooster or otherwise perform retransmissions without frequency shiftingsignals. Indeed in example embodiment, the retransmissions can be basedupon receiving a signal or guided wave and performing some signal orguided wave processing or reshaping, filtering, and/or amplification,prior to retransmission of the signal or guided wave.

Turning now to FIG. 5A, a block diagram illustrating an example,non-limiting embodiment of a communication system 500 in accordance withvarious aspects of the subject disclosure is shown. The communicationsystem 500 can include a macro base station 502 such as a base stationor access point having antennas that covers one or more sectors (e.g., 6or more sectors). The macro base station 502 can be communicativelycoupled to a communication node 504A that serves as a master ordistribution node for other communication nodes 504B-E distributed atdiffering geographic locations inside or beyond a coverage area of themacro base station 502. The communication nodes 504 operate as adistributed antenna system configured to handle communications trafficassociated with client devices such as mobile devices (e.g., cellphones) and/or fixed/stationary devices (e.g., a communication device ina residence, or commercial establishment) that are wirelessly coupled toany of the communication nodes 504. In particular, the wirelessresources of the macro base station 502 can be made available to mobiledevices by allowing and/or redirecting certain mobile and/or stationarydevices to utilize the wireless resources of a communication node 504 ina communication range of the mobile or stationary devices.

The communication nodes 504A-E can be communicatively coupled to eachother over an interface 510. In one embodiment, the interface 510 cancomprise a wired or tethered interface (e.g., fiber optic cable). Inother embodiments, the interface 510 can comprise a wireless RFinterface forming a radio distributed antenna system. In variousembodiments, the communication nodes 504A-E can include one or moreantennas, such as dielectric horn antennas or antenna arrays, poly rodantennas or antenna arrays or any of the other antennas describedherein. The communication nodes 504A-E can be configured to providecommunication services to mobile and stationary devices according toinstructions provided by the macro base station 502. In other examplesof operation however, the communication nodes 504A-E operate merely asanalog repeaters to spread the coverage of the macro base station 502throughout the entire range of the individual communication nodes504A-E.

The micro base stations (depicted as communication nodes 504) can differfrom the macro base station in several ways. For example, thecommunication range of the micro base stations can be smaller than thecommunication range of the macro base station. Consequently, the powerconsumed by the micro base stations can be less than the power consumedby the macro base station. The macro base station optionally directs themicro base stations as to which mobile and/or stationary devices theyare to communicate with, and which carrier frequency, spectralsegment(s) and/or timeslot schedule of such spectral segment(s) are tobe used by the micro base stations when communicating with certainmobile or stationary devices. In these cases, control of the micro basestations by the macro base station can be performed in a master-slaveconfiguration or other suitable control configurations. Whetheroperating independently or under the control of the macro base station502, the resources of the micro base stations can be simpler and lesscostly than the resources utilized by the macro base station 502.

Turning now to FIG. 5B, a block diagram illustrating an example,non-limiting embodiment of the communication nodes 504B-E of thecommunication system 500 of FIG. 5A is shown. In this illustration, thecommunication nodes 504B-E are placed on a utility fixture such as alight post. In other embodiments, some of the communication nodes 504B-Ecan be placed on a building or a utility post or pole that is used fordistributing power and/or communication lines. The communication nodes504B-E in these illustrations can be configured to communicate with eachother over the interface 510, which in this illustration is shown as awireless interface. The communication nodes 504B-E can also beconfigured to communicate with mobile or stationary devices 506A-C overa wireless interface 511 that conforms to one or more communicationprotocols (e.g., fourth generation (4G) wireless signals such as LTEsignals or other 4G signals, fifth generation (5G) wireless signals,WiMAX, 802.11 signals, ultra-wideband signals, etc.). The communicationnodes 504 can be configured to exchange signals over the interface 510at an operating frequency that is may be higher (e.g., 28 GHz, 38 GHz,60 GHz, 80 GHz or higher) than the operating frequency used forcommunicating with the mobile or stationary devices (e.g., 1.9 GHz) overinterface 511. The high carrier frequency and a wider bandwidth can beused for communicating between the communication nodes 504 enabling thecommunication nodes 504 to provide communication services to multiplemobile or stationary devices via one or more differing frequency bands,(e.g. a 900 MHz band, 1.9 GHz band, a 2.4 GHz band, and/or a 5.8 GHzband, etc.) and/or one or more differing protocols. In otherembodiments, particularly where the interface 510 is implemented via aguided wave communications system on a wire, a wideband spectrum in alower frequency range (e.g. in the range of 2-6 GHz, 4-10 GHz, etc.) canbe employed.

Turning now to FIG. 5C, a block diagram illustrating an example,non-limiting embodiment of downlink and uplink communication techniquesfor enabling a base station to communicate with the communication nodes504 of FIG. 5A is shown. In the illustrations of FIG. 5C, downlinksignals (i.e., signals directed from the macro base station 502 to thecommunication nodes 504) can be spectrally divided into control channels522, downlink spectral segments 526 each including modulated signalswhich can be frequency converted to their original/native frequency band(e.g., cellular band, or other native frequency band) for enabling thecommunication nodes 504 to communicate with one or more mobile orstationary devices 526, and pilot signals 524 which can be supplied withsome or all of the spectral segments 526 for mitigating distortioncreated between the communication nodes 504. The pilot signals 524 canbe processed by tethered or wireless transceivers of downstreamcommunication nodes 504 to remove distortion from a receive signal(e.g., phase distortion). Each downlink spectral segment 526 can beallotted a bandwidth 525 sufficiently wide (e.g., 50 MHz) to include acorresponding pilot signal 524 and one or more downlink modulatedsignals located in frequency channels (or frequency slots) in thespectral segment 526. The modulated signals can represent cellularchannels, WLAN channels or other modulated communication signals (e.g.,10-20 MHz), which can be used by the communication nodes 504 forcommunicating with one or more mobile or stationary devices 506.

Uplink modulated signals generated by mobile or stationary communicationdevices in their native/original frequency bands (e.g., cellular band,or other native frequency band) can be frequency converted and therebylocated in frequency channels (or frequency slots) in the uplinkspectral segment 530. The uplink modulated signals can representcellular channels, WLAN channels or other modulated communicationsignals. Each uplink spectral segment 530 can be allotted a similar orsame bandwidth 525 to include a pilot signal 528 which can be providedwith some or each spectral segment 530 to enable upstream communicationnodes 504 and/or the macro base station 502 to remove distortion (e.g.,phase error).

In the embodiment shown, the downlink and uplink spectral segments 526and 530 each comprise a plurality of frequency channels (or frequencyslots), which can be occupied with modulated signals that have beenfrequency converted from any number of native/original frequency bands(e.g. a 900 MHz band, 1.9 GHz band, a 2.4 GHz band, and/or a 5.8 GHzband, etc.). The modulated signals can be up-converted to adjacentfrequency channels in downlink and uplink spectral segments 526 and 530.In this fashion, while some adjacent frequency channels in a downlinkspectral segment 526 can include modulated signals originally in a samenative/original frequency band, other adjacent frequency channels in thedownlink spectral segment 526 can also include modulated signalsoriginally in different native/original frequency bands, but frequencyconverted to be located in adjacent frequency channels of the downlinkspectral segment 526. For example, a first modulated signal in a 1.9 GHzband and a second modulated signal in the same frequency band (i.e., 1.9GHz) can be frequency converted and thereby positioned in adjacentfrequency channels of a downlink spectral segment 526. In anotherillustration, a first modulated signal in a 1.9 GHz band and a secondcommunication signal in a different frequency band (i.e., 2.4 GHz) canbe frequency converted and thereby positioned in adjacent frequencychannels of a downlink spectral segment 526. Accordingly, frequencychannels of a downlink spectral segment 526 can be occupied with anycombination of modulated signals of the same or differing signalingprotocols and of a same or differing native/original frequency bands.

Similarly, while some adjacent frequency channels in an uplink spectralsegment 530 can include modulated signals originally in a same frequencyband, adjacent frequency channels in the uplink spectral segment 530 canalso include modulated signals originally in different native/originalfrequency bands, but frequency converted to be located in adjacentfrequency channels of an uplink segment 530. For example, a firstcommunication signal in a 2.4 GHz band and a second communication signalin the same frequency band (i.e., 2.4 GHz) can be frequency convertedand thereby positioned in adjacent frequency channels of an uplinkspectral segment 530. In another illustration, a first communicationsignal in a 1.9 GHz band and a second communication signal in adifferent frequency band (i.e., 2.4 GHz) can be frequency converted andthereby positioned in adjacent frequency channels of the uplink spectralsegment 526. Accordingly, frequency channels of an uplink spectralsegment 530 can be occupied with any combination of modulated signals ofa same or differing signaling protocols and of a same or differingnative/original frequency bands. It should be noted that a downlinkspectral segment 526 and an uplink spectral segment 530 can themselvesbe adjacent to one another and separated by only a guard band orotherwise separated by a larger frequency spacing, depending on thespectral allocation in place.

It will be appreciated that downlink modulated signals generated by abase station in their native/original frequency bands (e.g., cellularband, or other native frequency band) can be frequency shifted to one ofthe downlink spectral segments 526 without re-modulating the modulatedsignals. That is, frequency shifting the downlink modulated signals caninclude transitioning the downlink modulated signals from itsnative/original frequency bands to a spectral segment 526 withoutmodifying the signaling protocol (e.g., LTE, 5G, DOCSIS, etc.) and/orthe modulation technique (e.g., orthogonal frequency-division multipleaccess; generally, referred to as OFDMA, etc.) used by the base stationto generate the downlink modulated signal in its native/originalfrequency bands. Frequency shifting the downlink modulated signals inthis manner preserves the signaling protocol and/or modulation techniqueused to generate the downlink modulated signals, and thereby enables anyof the communication nodes 504 to restore the downlink modulated signalsin spectral segment 526 to its respective native/original frequencybands with only a frequency conversion process.

Similarly, uplink modulated signals generated by mobile or stationarycommunication devices in their native/original frequency bands (e.g.,cellular band, or other native frequency band) can be frequency shiftedto one of the uplink spectral segments 530 without re-modulating themodulated signals. That is, frequency shifting the uplink modulatedsignals can include transitioning the uplink modulated signals from itsnative/original frequency bands to a spectral segment 530 withoutmodifying the signaling protocol (e.g., LTE, 5G, DOCSIS, etc.) and/orthe modulation technique (e.g., single carrier frequency-divisionmultiple access; generally, referred to as SC-FDMA, etc.) used by themobile or stationary communication devices to generate the uplinkmodulated signal in its native/original frequency bands. Frequencyshifting the uplink modulated signals in this manner preserves thesignaling protocol and/or modulation technique used to generate theuplink modulated signals, and thereby enables any of the communicationnodes 504 to restore the uplink modulated signals in spectral segment530 to its respective native/original frequency bands with only afrequency conversion process.

The foregoing frequency conversion processes can correspond to afrequency up-conversion, a frequency down-conversion, or a combinationthereof. The frequency conversion process can be performed with analogcircuitry (e.g., amplifiers, mixers, filters, etc.) without digitalconversion, which can simplify the design requirements of thecommunication nodes 504. Frequency conversion can be also performed viadigital signal processing while preserving the signaling protocol and/ormodulation technique, for example, by shifting the signals in thefrequency domain. It will be appreciated that the foregoing principlesof frequency conversion without modifying the signaling protocol and/orthe modulation technique of previously modulated signals itsnative/original frequency bands can be applied to any embodiments of thesubject disclosure including without limitation wireless signalspropagating in free space between antenna systems of a distributedantenna system, and/or guided electromagnetic waves that propagate alonga physical transmission medium.

Turning now to FIG. 5D, a graphical diagram 560 illustrating an example,non-limiting embodiment of a frequency spectrum is shown. In particular,a spectrum 562 is shown for a distributed antenna system that conveysmodulated signals occupying frequency channels of uplink or downlinkspectral segments after they have been converted in frequency (e.g. viaup-conversion or down-conversion) from one or more original/nativespectral segments into the spectrum 562.

As previously discussed two or more different communication protocolscan be employed to communicate upstream and downstream data. When two ormore differing protocols are employed, a first subset of the downlinkfrequency channels of a downlink spectral segment 526 can be occupied byfrequency converted modulated signals in accordance with a firststandard protocol and a second subset of the downlink frequency channelsof the same or a different downlink spectral segment 530 can be occupiedby frequency converted modulated signals in accordance with a secondstandard protocol that differs from the first standard protocol.Likewise a first subset of the uplink frequency channels of an uplinkspectral segment 530 can be received by the system for demodulation inaccordance with the first standard protocol and a second subset of theuplink frequency channels of the same or a different uplink spectralsegment 530 can be received in accordance with a second standardprotocol for demodulation in accordance with the second standardprotocol that differs from the first standard protocol.

In the example shown, the downstream channel band 544 includes a firstplurality of downstream spectral segments represented by separatespectral shapes of a first type representing the use of a firstcommunication protocol. The downstream channel band 544′ includes asecond plurality of downstream spectral segments represented by separatespectral shapes of a second type representing the use of a secondcommunication protocol. Likewise the upstream channel band 546 includesa first plurality of upstream spectral segments represented by separatespectral shapes of the first type representing the use of the firstcommunication protocol. The upstream channel band 546′ includes a secondplurality of upstream spectral segments represented by separate spectralshapes of the second type representing the use of the secondcommunication protocol. These separate spectral shapes are meant to beplaceholders for the frequency allocation of each individual spectralsegment along with associated reference signals, control channels and/orclock signals. While the individual channel bandwidth is shown as beingroughly the same for channels of the first and second type, it should benoted that upstream and downstream channel bands 544, 544′, 546 and 546′may be of differing bandwidths. Additionally, the spectral segments inthese channel bands of the first and second type may be of differingbandwidths, depending on available spectrum and/or the communicationstandards employed.

Turning now to FIG. 5E, a graphical diagram 570 illustrating an example,non-limiting embodiment of a frequency spectrum is shown. In particulara portion of the spectrum 562 of FIG. 5D is shown for a distributedantenna system that conveys modulated signals in the form of channelsignals that have been converted in frequency (e.g. via up-conversion ordown-conversion) from one or more original/native spectral segments.

The portion 572 includes a portion of a downlink or uplink spectralsegment 526 and 530 that is represented by a spectral shape and thatrepresents a portion of the bandwidth set aside for a control channel,reference signal, and/or clock signal. The spectral shape 574, forexample, represents a control channel that is separate from referencesignal 579 and a clock signal 578. It should be noted that the clocksignal 578 is shown with a spectral shape representing a sinusoidalsignal that may require conditioning into the form of a more traditionalclock signal. In other embodiments however, a traditional clock signalcould be sent as a modulated carrier wave such by modulating thereference signal 579 via amplitude modulation or other modulationtechnique that preserves the phase of the carrier for use as a phasereference. In other embodiments, the clock signal could be transmittedby modulating another carrier wave or as another signal. Further, it isnoted that both the clock signal 578 and the reference signal 579 areshown as being outside the frequency band of the control channel 574.

In another example, the portion 575 includes a portion of a downlink oruplink spectral segment 526 and 530 that is represented by a portion ofa spectral shape that represents a portion of the bandwidth set asidefor a control channel, reference signal, and/or clock signal. Thespectral shape 576 represents a control channel having instructions thatinclude digital data that modulates the reference signal, via amplitudemodulation, amplitude shift keying or other modulation technique thatpreserves the phase of the carrier for use as a phase reference. Theclock signal 578 is shown as being outside the frequency band of thespectral shape 576. The reference signal, being modulated by the controlchannel instructions, is in effect a subcarrier of the control channeland is in-band to the control channel. Again, the clock signal 578 isshown with a spectral shape representing a sinusoidal signal, in otherembodiments however, a traditional clock signal could be sent as amodulated carrier wave or other signal. In this case, the instructionsof the control channel can be used to modulate the clock signal 578instead of the reference signal.

Consider the following example, where the control channel 576 is carriedvia modulation of a reference signal in the form of a continuous wave(CW) from which the phase distortion in the receiver is corrected duringfrequency conversion of the downlink or uplink spectral segment 526 and530 back to its original/native spectral segment. The control channel576 can be modulated with a robust modulation such as pulse amplitudemodulation, binary phase shift keying, amplitude shift keying or othermodulation scheme to carry instructions between network elements of thedistributed antenna system such as network operations, administrationand management traffic and other control data. In various embodiments,the control data can include without limitation:

-   -   Status information that indicates online status, offline status,        and network performance parameters of each network element.    -   Network device information such as module names and addresses,        hardware and software versions, device capabilities, etc.    -   Spectral information such as frequency conversion factors,        channel spacing, guard bands, uplink/downlink allocations,        uplink and downlink channel selections, etc.    -   Environmental measurements such as weather conditions, image        data, power outage information, line of sight blockages, etc.

In a further example, the control channel data can be sent viaultra-wideband (UWB) signaling. The control channel data can betransmitted by generating radio energy at specific time intervals andoccupying a larger bandwidth, via pulse-position or time modulation, byencoding the polarity or amplitude of the UWB pulses and/or by usingorthogonal pulses. In particular, UWB pulses can be sent sporadically atrelatively low pulse rates to support time or position modulation, butcan also be sent at rates up to the inverse of the UWB pulse bandwidth.In this fashion, the control channel can be spread over an UWB spectrumwith relatively low power, and without interfering with CW transmissionsof the reference signal and/or clock signal that may occupy in-bandportions of the UWB spectrum of the control channel.

In one or more embodiments in system 600 of FIG. 6, communication device610 can include an antenna array 615 for transmitting wireless signals.In one or more embodiments, the antenna array 615 can perform beamsteering. For example, the antenna array 615 can utilize a first subsetof antennas of the antenna array to transmit first wireless signals 625directed (as shown by reference number 627) via beam steering towardsthe communication device 650. A second subset of antennas of the antennaarray 615 can transmit second wireless signals 630 directed (as shown byreference number 632) via the beam steering towards a transmissionmedium 675 (e.g., a power line connected between the utility poles 620,660). In one or more embodiments, the aforementioned beams can besimultaneously created by the same set of antennas in arrays 610 and650. In one or more embodiments, the beam steering can enable theantenna array to communicate with more than one wireless receiver withor without directing wireless signals to a transmission medium. In oneor more embodiments, the beam steering can enable the antenna array todirect the wireless signals to more than one transmission medium with orwithout communicating with a wireless receiver.

The first and second wireless signals 625, 630 can be associated withcommunication signals that are to be transmitted over the network. Forinstance, the first and second wireless signals 625, 630 can be the samesignals. In another example, the first wireless signals 625 canrepresent a first subset of the communication signals, while the secondwireless signals 630 represent a second subset of the communicationsignals. In one embodiment, the first and second wireless signals 625,630 can be different and can be based on interleaving of a group ofcommunication signals, such as video packets, and so forth. Thecommunication signals can be various types of signals includinginformation associated with subscriber services, network control,testing, and so forth.

In one or more embodiments, the second wireless signals 630 induceelectromagnetic waves 640. For example, the electromagnetic waves 640are induced at a physical interface of the transmission medium 675 andpropagate (as shown by reference number 642) without requiring anelectrical return path. The electromagnetic waves 640 are guided by thetransmission medium 675 towards the communication device 650, which ispositioned in proximity to the transmission medium. The electromagneticwaves 640 can be representative of the second wireless signals 630 whichare associated with the communication signals.

In one or more embodiments, the communication device 650 can include areceiver that is configured to receive the electromagnetic waves 640that are propagating along the transmission medium 675. System 600enables the communication device 610 to transmit information which isreceived by the communication device 650 (e.g., another antenna array655) via the wireless communication path 627 and via being guided by thetransmission medium 675.

In one or more embodiments, the antenna arrays 615, 655 can includepolyrod antennas. For example, each of the polyrod antennas can includea core that is connected with a waveguide that is configured to confinean electromagnetic wave at least in part within the core in a particularregion of the core. In one embodiment, each of the polyrod antennas caninclude a core having a first region, a second region, a third region,and a fourth region, where the core comprises an interface in the firstregion. One of the plurality of transmitters can generate a firstelectromagnetic wave that induces a second electromagnetic wave at theinterface of the first region. The core can be connected with awaveguide that is configured to confine the second electromagnetic waveat least in part within the core in the first region, where the secondregion of the core is configured to reduce a radiation loss of thesecond electromagnetic wave as the second electromagnetic wavepropagates into the second region. The third region of the core can beconfigured to reduce a propagation loss of the second electromagneticwave as the second electromagnetic wave propagates into the thirdregion. The fourth region of the core can be outside of the waveguideand can be tapered to facilitate transmitting one of the first or secondwireless signals based on the second electromagnetic wave.

In one or more embodiments, the communication device 610 can provide aphase adjustment to the second wireless signals 630 to accomplish beamsteering towards the transmission medium 675. FIG. 6 illustrates theantenna array 655 and the receiver 665 being co-located at communicationdevice 650, however, in another embodiment the antenna array 655 and thereceiver 665 can be separate devices that may or may not be in proximityto each other. For example, the first wireless signals 625 can bereceived by the antenna array 655 of the communication device 650 whilethe electromagnetic waves 640 can be received by a receiver of adifferent communication device (not shown) that is in proximity to thetransmission medium 675.

The foregoing embodiments can be combined in whole or in part with theproceeding techniques for processing electromagnetic waves having afield structure that facilitates a reduction of propagation losses whenan obstruction such as water is present on an outer surface of atransmission medium such as a cable, power line, or other physicalstructure. In an embodiment, an approach for low-loss propagation ofelectromagnetic modes on a single conductor wire can include utilizinghigher-order modes to tailor the field distribution of anelectromagnetic wave and optimize the mode's sensitivity to the presenceof both a water film and water droplets on a wire, while maintaining areasonable transverse power profile and strong guidance.

Example embodiments of the subject disclosure also include communicationdevices that can launch/transmit or receive electromagnetic waves thatpropagate along a physical transmission medium and that have anelectromagnetic field spatially configured to avoid in whole or in partenergy loss or leakage n. In an example embodiment, theseelectromagnetic waves can be described as a hollow mode or a donut modein which the electromagnetic field has a first portion with a higherenergy intensity (e.g., the donut portion excluding the hole) than thatof a second portion (e.g., the hole of the donut). In an exampleembodiment, the first portion of the electromagnetic field may besubstantially concentric with the second portion of the electromagneticfield. It will be appreciated, however, that asymmetric or symmetricfield configurations of the donut mode may be used. Theseelectromagnetic waves can also be described as having a Bessel orBessel-Gauss-like field structure, as described herein. Whilecommunication devices are described herein as launching/transmitting orreceiving Bessel or Bessel-Gauss-like TM modes, it will be appreciatedthat these communication devices could also be configured to operatewith other hollow modes or donut modes without departing from exampleembodiments of the subject disclosure.

In accordance with example embodiments, example communication devicescan be configured to utilize or operate with (e.g., launch/transmit,receive, etc.) one or more modes in a class of Bessel-Gauss-like TMmodes, which can meet requirements in a variety of operationalconditions including: the presence of water films and droplets on thetransmission medium, wire curvature and helicity of the transmissionmedium, with and without insulation on the transmission medium, and/orover a large range in operational frequency and transmission mediumlength. As described further herein, these conditions can be simulatedusing multiple simulation techniques consisting of periodic eigenmode;frequency and time domain driven modal; and an electric field integralequation solver. These techniques are believed to be in good agreementwhen simulating systems that operate under the same conditions. Thesubject disclosure also identifies communication devices or antennas tolaunch these modes and couple them to wires for subsequent experimentaltesting.

Results from simulation tests provide as follows:

-   -   a Bessel-Gauss-like TM₁ mode, with simulations of up to 25 m        length with curvature, may have an operational bandwidth of 8-24        GHz with 0.2 dB/m loss when accounting for a 0.1 mm water film        thickness on the outer surface of the transmission medium.    -   a Bessel-Gauss-like TM₁₁ mode, with simulations with eigenmode        and frequency domain solvers over short distances, may meet        operational requirements even with a water film on at least a        portion of the outer surface of the transmission medium.    -   Completing benchmarking simulations for comparison with        experimental measurements of the Sommerfeld mode.    -   Over 400,000 CPU compute hours were conducted at NERSC        simulating electromagnetic mode propagation on curved wires with        water films.

In accordance with the foregoing analysis and simulations,super-positioning of higher order modes may be utilized to tailor thefield profile on the wire and adjust the guidance of the electromagneticwave. The subject disclosure describes the optimization and propagationof these modes in a variety of operational conditions. For illustrationpurposes only, the subject disclosure refers to these modes asBessel-Gauss-like, because the fields may be easier to describe with aBessel-Gauss formalism. This formalism may be convenient in that itlimits the number of free parameters that describe the fielddistribution to primarily two: the Bessel index and the beam waist. Itwill be appreciated that these field distributions could also bedescribed accurately with a sum of Hankel functions, but it wouldrequire more parameters as many Hankel functions must be superimposed toforce the fields to zero beyond a given radius. Simulations confirm thatthese field distributions in the absence of a transmission medium/wiredo expand as expected for a Bessel-Gauss beam in free space. Simulationsfurther demonstrate that the propagation of the Bessel-Gauss-like modeis significantly altered by the presence of the transmission medium/wireand water which provide guidance.

The subject disclosure that follows includes:

-   -   benchmarking theoretical modeling against an existing problem        set, simulations and experiments;    -   evaluating guided mode propagation in a realistic geometry to        illustrate solution(s) for low loss propagation in rainfall;    -   analyzing solution(s) and attenuation with numerical and        computational modeling of real world problems and variations,        e.g., rainfall, wire sag, insulation, cable helicity;    -   understanding scaling with frequency and highest bandwidth        operating points; and    -   evaluating solution(s) consistency with QAM/communications        requirements.

Simulation Tools Utilized for Analysis

A variety of simulation tools were used to analyze the propagation ofelectromagnetic modes (e.g., Periodic Eigenmode Simulations, ACE3P—ATime and Frequency Domain Finite Element Solver, and Electric FieldIntegral Equation Modeling). These simulations will now be described infurther detail for illustrative purposes.

a) Periodic Eigenmode Simulations

Eigenmode simulations provide fast and accurate solutions to periodicsystems and can be implemented to analyze the modes propagating onwaveguides. This approach can be utilized with single conductor wires tosolve for propagating modes. An example of a simulation domain is shownin FIG. 7A1 with periodic boundary conditions in the longitudinaldimension and a perfectly matched layer (PML) boundary on the outerradius to absorb radiation from the mode. In FIG. 7A2 we show an exampleof the TM₀ mode at 20 GHz. In FIG. 7A3 we show a comparison betweentheory and simulation for the radial and longitudinal electric field vsradial distance.

b) ACE3P—A Time and Frequency Domain Finite Element Solver

ACE3P (Advanced Computational Electromagnetics 3D Parallel), developedat Standard Linear Accelerator Center (SLAC), is a comprehensive set ofparallel finite-element multi-physics codes including electromagnetic,thermal and mechanical characteristics for high-fidelity simulation ofRF and accelerator structures. ACE3P runs on Department of Energy (DOE)supercomputing resources at the National Energy Research ScientificComputing Center (NERSC) and thus can handle large-scale computationalproblems.

i) T3P. T3P, the 3-dimensional (3D) time domain electromagnetic solverin ACE3P, was used for modeling power and signal propagation on a singlewire. T3P has a good scaling on the most advanced supercomputer Cori atNERSC as shown in FIG. 7B. The computational time can be reduced byusing more compute cores on the machine. A “moving window” simulationwas implemented in T3P. The moving window utilizes a pulsed excitationof the simulation domain and only solves for the fields in a volume thatis surrounding the finite extent of the pulse. This approach drasticallyreduces the computational hours needed for time domain simulations,which is critical given the incredibly large meshes for this class ofproblems.

For benchmarking, a coax feed is used to launch a Sommerfeld TM₀ modepulse at 5 GHZ was driven at the input port of a 50 m long bare smoothcopper wire with finite surface conductivity. The computational domainis constrained within 200 mm in the radial direction, and an absorbingboundary condition is set at the outbound surface to ensure minimalreflection of electromagnetic field back to the computational domain. Asnapshot in time of the electric field from the T3P simulation ispresented in FIG. 7C with an expanded view of the pulse in the top leftcorner. It clearly shows that the principle TM₀ mode is coupled to thecopper wire. The TM₀ mode attenuation is found to be 0.08 dB/m thatincludes the mode coupling loss from TEM to TM₀ at the input port.

A comparison for two equivalent simulations of 50 m wire at 5 GHz, withand without a moving window, is shown in Table 1.

TABLE 1 Comparison between computational time with and without movingwindow for model shown in FIG. 7C. Wire Moving Compute Length (m) dT(ps) CPU DOF Window Time (min.) 5 GHz 50 5 640 7M No 450 5 GHz 50 5 6407M Yes 35

ii) S3P. S3P, the 3-dimensional (3D) frequency domain electromagneticsolver in ACE3P, was used for modeling power and signal propagation on asingle wire. S3P calculates the S-parameters of electromagneticstructures by solving Maxwell's equations cast as a harmonic Helmholtzequation at a specified frequency. The excitations into thecomputational domain are realized using ports at the surface boundariesof the computational domain. The port modes are solved numerically andloaded at the ports for the S-parameter calculation. FIG. 7D shows anexemplary simulation of the TM₀ on a curved wire at 5 GHz.

c) Electric Field Integral Equation Modeling

We evaluated the use of electric field integral equation (EFIE) methodfor computation of the propagation of a field guided by a singleconductor. For a perfect conducting surface this method yields anequation for the unknown surface current Js on the conductor induced bya known incident field E^(i) as:

${E^{i}(r)} = {{- \frac{{jk}\; \eta}{4\pi}}{\int{\left( {I - {\nabla\nabla^{\prime}}} \right)\frac{\exp \left( {- {{jk}\left( {r - r^{\prime}} \right)}} \right)}{{r - r^{\prime}}}{J_{s}\left( r^{\prime} \right)}{ds}^{\prime}}}}$

After finding the solution for surface currents the total field,E^(i)+E^(s)(Js), can then be computed to calculate quantities ofinterest such as propagation loss. Using this formulation as shown inFIG. 7E, with a horn we excite the Sommerfeld mode at 30 GHz, wecalculated the propagation of the excited fields on a 10 meter length ofwire with a 0.5 cm radius.

Benchmarking Simulations

A measurement of a single wire transmission was performed using twoback-to-back horns (FIG. 7F) which convert an input coaxial TEM mode toa Sommerfeld-like wave that propagates on the wire connecting the horns.In this section, the subject disclosure demonstrates two computationalmethods that can be used for calculation of transmission in thisconfiguration. A first computation uses the mode matching method whichprovides a rapid solution (seconds) but does not model diffractioneffects or the free space transmission of fields on a single wire. Asecond method based on the electric field integral method provides afull wave solution of the problem but is computationally demanding(hours/days) and assumes perfect conductivity.

TABLE 2 Calculated mode content at horn radiating aperture andtransmission estimate for complete transmission experiment using the twohorns. The numbers for modal power content are normalized to total powerat the horn output aperture. Back-to-Back Estimate Freq Modal PowerContent at Horn Aperture Reflected Insertion Loss (GHz) TEM TM01 TM02TM03 TM04 TM05 TM06 Power (%) (dB) 5 66.3 30.6 3.1 20 −5.4 10 56.3 24.614.6 4.1 8 −5.7 20 49.2 27.4 10.3 6.3 4.5 1.7 20 −7.6 30 45.4 25.2 10.69.3 4.3 1.5 1.3 3 −6.8 40 46.4 19.1 14.8 8.8 4.5 3.4 1.4 2 −7.5 50 15.46.9 8.4 3.1 12.5 15.8 10.3 2 −16.6

Mode Matching

The mode matching (MM) method is based on an expansion of the fields inthe waveguide in terms of the modes of a cylindrical waveguide. At eachchange in the waveguide radius (smoothly varying walls are modeled as aseries of small steps) the field expansion is matched across the commonaperture to ensure continuity of the electric and magnetic fields. Thisapproach is known to give an accurate multimode scattering matrix forrectangular, circular and coaxial waveguide geometries. The modematching method is well suited for modeling the coax feed and horngeometry but does not provide a solution for the open single wiretransmission as this is no longer a closed waveguide geometry. However,for aperture sizes much greater than a wavelength, the computed fieldsat the horn's radiating aperture do provide a very good approximation ofthe actual fields radiating into space on the single conductor. The mainapproximation error arises from diffraction due to non-zero fields onthe horn's outer edge, which is not included in the mode matchingcalculation. For the horn output aperture dimensions, the error fromneglecting the diffraction fields is small as the TEM electric fieldintensity is about −25 dB lower at the aperture edge versus the fieldintensity on the center conductor. The power coupled to the Sommerfeldmode will be given to a close approximation by the calculated power inthe TEM mode.

The primary contributor to fluctuations in power in the desired outputTEM mode is from mode conversion and reflection in the coax feed portionof the horn. This can be seen in FIG. 7G. The TEM transmission for thehorn only is somewhat smooth versus frequency, starting at −2 dB anddecreasing to −3.5 dB at 50 GHz. The calculation with the combined coaxfeed and horn shows significant variations in transmission due tocomplex interactions between the higher order modes generated in thefeed and mode conversion in the horn. The mode composition breakdown ofTEM power and power in higher order modes calculated for the coax feedand horn together is shown in Table 2. Also shown in the last twocolumns of Table 2 is an estimate for the transmission that was observedin the experiment with two horns connected by the single conductor. Thetransmission estimate was calculated as:

Insertion Loss (dB)=2×10 Log 10[fractional power in TEMmode(1−fractional reflected power)].

This estimate has two approximations which are: (i) it assumes the powerof the propagating mode on the wire is equal to the TEM mode content atthe horn aperture and (ii) does not include ohmic and diffraction lossesalong the wire connecting the two horns.

Electric Field Integral Equation

In the electric field integral equation (EFIE) method metal surfaces arereplaced by surface currents whose radiated fields satisfy the originalboundary condition that the tangential electric field (sum of incidentand radiated fields) is zero on the surfaces and total field goes tozero at infinity (radiation boundary condition). From the equivalencetheorem it is given that the total field derived with the EFIEformulation is identical to the original problem. Solution for theinitially unknown surface currents requires an iterative solution of alarge, dense matrix which is computationally very demanding but less sothan a finite element solution when the total surface area is largecompared to wavelength such as for this case of interest.

We have evaluated the transmission for the horn and wire geometry usingthe EFIE with perfect conductors. The metallic surfaces are modeled witha triangular mesh on which a basis set representing the unknown surfacecurrents is placed. An example for a generated mesh is shown in FIG. 7H,which shows the horns and conducting wire connecting the two. For thereceiving horn a second horn is used to act as a terminating load. Thiswas necessary as a sudden termination of the inner conductor on thesmall diameter end of the receiving horn would result in a reflection ofthe power back into the horn and affect the transmission calculation.Numerical experiments showed this free space “load” has a powerreflection of less than 1%.

Example calculations showing field intensity of the radial electricfield for the horn and wire transmission are presented in FIG. 7I. Thefield pattern generated by the horn does not match the guided wire modeexactly so the transverse field profile changes over the first 100-200cm as the non-guided field components radiate away from the wire. Afterthis point the transverse field profile is constant but reducing inamplitude as part of the field diffracts away from the wire. At thereceiving end of the horn there is a reflection as the guided modeprofile does not match the horn aperture field that would couple to aTEM coax waveguide mode. This can be seen by the abrupt change in thetransverse field profile and the standing wave pattern (due to thereflected field) in the vicinity of the receiving horn.

An estimate for the coupling of the coaxial waveguide TEM mode to theguided wire mode, and the propagation loss of that mode, can be obtainedby calculation of the power flow (integration of E X H* on a planetransverse to the wire direction) versus distance with an integrationradius of the horn radius. The result for this calculation performed forthe 20 GHz simulation is shown in FIG. 7J(a). The power flow dropsrapidly (due to diffracted power propagating beyond the radius ofintegration for the power flow) for the first 200 cm at which point thedecay rate decreases significantly indicating a field propagating alongthe wire with diffraction losses. An estimate for that loss can beobtained from the slope of the decay which for this case is 0.3 dB/m.The loss estimate for coupling of the coaxial TEM mode to the guidedwire mode is obtained by the ratio of power at the horn aperture to thepoint where the power decay is approximately linear and is 3.3 dB. Thisloss is very close to the 3 dB estimate obtained using the MM solutionwith the assumption that the coupling loss is equal to the fractionalpower in the TEM coax waveguide mode. What appears to be a rapid decayof the power flow at the wire end is due to the power reflected at thereceiving horn subtracting from the forward power flow in theintegration of E X H*. This reflected power rapidly diffracts outside ofthe region of integration for the power flow so only impacts the forwardpower flow calculation over approximately the last 100 cm.

The effect of the actual six strand configuration used for the wire inthe measurement was examined by generation of a mesh with a surfacedefined as R(ϕ,z)=Ro+dr Sin(Np/2(ϕ+2π z/pitch))² where Np is the numberof strands (FIG. 7J(b)). The calculation at 20 GHz was repeated usingthis model for the six-strand case and the results were essentiallyunchanged (see “Six Strand Wire” plot on FIG. 7J(a)). A plot of thetransverse field for this case is shown in FIG. 7J(c) which shows fieldenhancement on the outer radii of the six strands.

Table 3 compares the transmission estimates for the MM and EFIEcalculations over a frequency range from 5 to 30 GHz. It is observed forthe horn only calculations (EFIE calculations were done with only thehorn to reduce computation time) that there is relatively good agreementbetween the two approaches. This suggests that MM method (with theinclusion of a model which accounts for propagation loss along the wirelength) can be used as a way to obtain rapid estimates for transmissionloss over wide ranges of frequency and wire configurations (length, dry,wet, sag,etc.).

TABLE 3 Comparison of transmission loss estimates for MM and EFIEcalculation methods. Transmission Loss (dB) MM MM EFIE Freq (GHz) Hornand coax feed Horn only Horn only 5 −5.4 −3.5 −5 10 −5.7 −5.2 −4.9 15−6.4 −5.2 −5.5 20 −7.6 −6.4 −8 30 −6.8 −6.7 −7.6

Bessel-Gauss Modes

From simulations for the fundamental TM₀ mode, it was observed thatpropagation losses are dominated by absorption due to the presence ofthe water film. These losses are high and increase dramatically withfrequency, as shown in FIG. 7K, rendering operation above 10 GHzchallenging. It was not observed that radiation losses or modeconversion to be a dominant loss. It was noted that, due to the highdielectric constant, a uniform thickness of water coating the wire doesalter the field profile of a mode especially at higher frequency. Inlarge scale simulations, problems were not observed with mode conversiondue the shape of the wire for the fundamental TM₀ mode; however, forhigher order modes this may be a concern. In order to decreaseabsorption losses in the water film the relative power density on thesurface of the wire must be reduced. Additionally, non-azimuthallysymmetric field distributions may prove advantageous to limit the impactof water beads on the surface. Given these conditions, the candidatemodes could be simulated using the following constraints:

-   -   Decrease the field intensity on the wire relative to the power        flow;    -   Pursue non-azimuthally uniform modes;    -   Limit the transverse extent of the mode to 0.2 m for practical        implementation;    -   Seek modes that would be less sensitive to bends on the        wire—these modes would show some response to the presence of        water on the wire;    -   Balance absorption loss with guidance.

a) Bessel-Gauss-like TM₁ mode at 25 GHz. The most extensive modelingthat was performed on the Bessel-Gauss-like TM₁ mode at 25 GHz. Asignificant amount of focus was placed on this frequency range for tworeasons. First, the losses on the TM₀ mode at 25 GHz are extreme, >−2dB/m, allowing testing in a challenging environment to demonstrate itsefficacy. Second, simulations and analysis of an approach that wassuccessful at this frequency would allow significant amounts ofbenchmarking and validation prior to extending this approach higher infrequency where computational constraints are dramatically increased.

b) Key Attributes of the Bessel-Gauss-like TM₁ mode at 25 GHz. TheBessel-Gauss-like TM₁ mode at 25 GHz meets many of the criteria that weset forth for providing a practical solution to the challenge oflow-loss propagation on a single conductor wire with a water coating.The key attributes of this mode are:

-   -   Decreased field intensity around the wire relative to overall        power flow—required to avoid extreme loss at high frequency;    -   Finite transverse extent with fields tapering off by 0.2 m        addresses the practical limit to the transverse extent of        launchers;    -   Not azimuthally uniform—required for water beading.

c) Analytical and Numerical Definition of the Bessel-Gauss-like TM₁.While the complete field distribution can only be described numericallyor as a superposition of modes, the fields of the Bessel-Gauss-like TM₁can be approximately described by a single Bessel-Gauss beam. In FIG. 7Lthe plot of the Bessel-Gauss beam most closely resembles theBessel-Gauss-like TM₁. The fields for the Bessel-Gauss beam are plottedfor the m=1 mode with ω_(o)=12.5λ where λ=c/f and the frequency is 25GHz. This mode is linearly polarized in the {circumflex over (x)}direction for FIG. 7L (see, for example, Hall, Dennis G. “Vector-beamsolutions of Maxwell's wave equation.” Optics letters 21.1 (1996):9-11).

To provide a complete description of the electromagnetic fields for theBessel-Gauss-like TM₁ we will provide the numerical values for E and Hon a transverse plane derived from the numerical solution. These fieldsare used for the plots shown in FIG. 7M. This mode is linearly polarizedin the ŷ direction for FIG. 7L.

d) Excitation of the Bessel-Gauss-like TM₁. The excitation of theBessel-Gauss-like TM₁ for electromagnetic simulations can beaccomplished with a variety of approaches. The fields can be solved forwith an eigenmode solver, the fields can be excited with a waveport, orthe fields can be excited with a mode converter. Here we present detailsof those three approaches.

i) Eigenmode Simulations. Solving for the field distribution of thismode can be performed with eigenmode simulations from commercialelectromagnetic solvers (e.g., HFSS is used for our simulations, orComputer Simulation Technology—CST's simulation tools, which arereferred herein as CST). The setup of an eigenmode simulation willrequire a few key steps that are described here assuming the wire lengthis in the 2 direction, see FIG. 7N. To begin, it is recommended to use a¼ symmetric solution to minimize the size of the mesh and number ofmodes. Define four concentric cylindrical sections with a longitudinalthickness Δz=2 mm and for each subsequent section a radial extent: wireΔr=5 mm, thin film layer Δr=0.1 mm, air Δr=199.9 mm, PML Δr>5 mm. Assigna finite conductivity boundary condition to the wire surface.

Assign the appropriate dielectric constant to the thin film layerwhether water or air. On the two sets of surfaces in the x-y planeassign a master/slave boundary condition with a phase advance Δφ=62°.This phase advance forces a traveling wave solution. Apply a perfect-Eboundary on the x-z plane and a perfect-H boundary on the y-z plane.These symmetry boundary conditions are required for the linearlypolarized solution in ¼ symmetry. Note that the boundary conditions forboth the Master/Slave and the symmetry planes should extend on the PML.This will result in an eigenmode solution at approximately 25.8 GHz forthe Bessel-Gauss-like TM₁. It is recommended that this procedure beapplied first to solving the TM₀ mode to verify the efficacy of themodel. For the TM₀ mode two changes will be required, first theperfect-E boundary should be replaced with a perfect-H boundary andsecond the phase advance Δφ may differ slightly.

Reproducing this simulation in CST will require the activation of thenonlinear eigensolver and the use of open boundaries where a PML isshown in FIG. 7N.

ii) Waveport Excitation for Frequency or Time-Domain Simulations. Forelectromagnetic simulations in frequency or time domain, external modeexcitation can be realized using ports at surface boundaries of acomputational domain. The modes are solved as a 2-dimensional eigenvalueproblem, which calculates the cutoff frequency of the propagating modesfrom the eigenvalues, and, the electric and magnetic fields from theeigenvectors. The eigenmodes are loaded at a port to enable excitationinto the computational domain as well as to allow non-reflectedtermination of electromagnetic fields propagating out of thecomputational domain. Typical 2-dimensional eigensolvers for waveportscan solve for modes without losses at the boundaries, such as TEM, TEand TM modes propagating in waveguides. For example, they do not solvefor modes with lossy boundary conditions, for example, absorbingboundary condition (ABC) and impedance boundary condition.

The Sommerfeld TM₀, Bessel-Gauss-like TM₁ and Bessel-Gauss-like TM₁₁modes used for this illustrative investigation are free-space modes thatare not confined as typical modes in waveguides. The field distributionsof these modes cannot be obtained by ACE3P's 2-dimensional eigensolverthat are required as sources of external excitations. However, ACE3Pprovides a capability to read in the transverse electric and magneticfield components of these modes obtained by other means, eitheranalytically or numerically. The resulting field map acts as theexcitation source in a similar manner as the numerical solution obtainedby ACE3P for waveguide modes, and also respects the lossy boundaryconditions that are imposed in the actual simulation. Therefore, in oursimulation tools (ACE3P T3P/S3P) we can define a field distribution fora waveport and use it to excite a driven modal simulation in frequencyor time domain. We export the fields from eigenmode simulations and usethose to drive the excitation in our simulations. A frequency domainexample is shown in FIG. 7O.

In accordance with CST, the Bessel-Gauss-like TM₁ mode may be excitedusing a “near-field source” (term used by CST) to reproduce the sameeffect. This near-field source in CST is based on the equivalenceprinciple allowing for the fields on an enclosed surface to represent asource inside of that volume. By importing the fields solved from theeigenmode solver we can excite a system with an equivalent “TM₁waveport”.

iii) Excitation with a Mode Converter. The Bessel-Gauss-like TM1 can beexcited in a full-wave electromagnetic solver code with a waveportcoupled to a mode converter or horn. Optimized (bandwidth, efficiency,compactness, robustness multi-mode operation, etc.) simulations can beperformed to design these sources. An example design approach isdescribed below for simulations. An effective method to convert a TE₁₁coaxial mode into a desired Bessel-Gaussian beam mode is to use acircular horn with a non-linear taper (see FIG. 7P1A(c) and FIGS.7P1B-7P1F). The taper profile is generated by computer optimization toproduce a mode mixture (TE11, TM11, TE12) through mode conversion, whichcan approximate the Bessel-Gaussian beam profile at the horn aperture.The optimization goal function to maximize in the computer optimizationof the taper profile is given by

Σ_(n) a_(n) ∫{right arrow over (E)}_(oo)(r,ϕ)·{right arrow over (E)}_(n)ds

where E_(oo) is the desired Bessel-Gaussian electric field profile andE_(n) are the orthonormalized waveguide mode functions of amplitudesa_(n) at end of the non-linear taper. We have implemented this approachfor a taper design using the mode-matching method to calculate the a_(n)modal amplitude coefficients, shown in FIG. 7P1A.

It will be appreciated that the embodiments of FIG. 7P1A can be adaptedaccording to other embodiments. For example, in the illustration of FIG.7P1B a tapered dielectric coating can be disposed on a transmissionmedium (e.g., a wire) to ease a transition of electromagnetic waves fromthe transmission medium to the coupler and vice-versa. This coating canreduce the transverse extent of a wave mode. The coating can be locatedinside and/or outside of a coupler (see, for example, horn of 7P1A(c)).The coating taper profile can be adapted both longitudinally andazimuthally to improve coupling of electromagnetic waves between acoupler and the transmission medium. The taper can also consist ofmultiple layers of dielectric material. FIG. 7P1C depicts couplergeometry profiles for excitation of a TM1 at 5 GHz and 12.5 GHz,respectively, about a 5 mm wire. FIG. 7P1D depicts a simulationperformance of the coupler of FIG. 7P1C at 5 GHz. FIG. 7P1E depicts asimulation performance of the coupler of FIG. 7P1C at 12.5 GHz. FIG.7P1F depicts a coupler with a non-uniform inner dimension. In thisillustration, an inner surface of the coupler does not have a constantradius. An inner volume of the coupler can be adapted with a dielectricmaterial constructed from a dielectric layer or multipledielectrics/layers. The inner volume of the coupler may also consist ofmultiple longitudinal segments of dielectrics and/or metals.

FIG. 7P2 is a graphical diagram illustrating, an example, non-limitingembodiment of a desired beam structure of an electromagnetic wavecentered about a wire in accordance with various aspects describedherein. The coupler shown in FIG. 7P1A(c) (or in FIGS. 7P1B-7P1F) can beconstructed with an aperture 702 that is of a sufficient diameter (2A₀)to produce a desired depth of focus 704 that enables the formation of aBessel-shaped electromagnetic wave 706 that can propagate along a wire708 (or other physical transmission medium that enables guidance of sucha wave). The larger the depth of focus 704 the greater the intensity orconcentration of the electromagnetic fields of the Bessel-shapedelectromagnetic wave, which in turn reduces diffraction (or leakage) ofthe electromagnetic wave as it propagates along the wire 708 (or otherphysical structure). Diffraction in the present context representsleakage of electromagnetic energy associated with an electromagneticwave into free space.

FIG. 7P3 is a graphical diagram illustrating, an example, non-limitingembodiment of a front-view of an aperture of a coupler 710 in accordancewith various aspects described herein. The coupler 710 of FIG. 7P3represents an alternative embodiment to the non-linear profile of thecoupler illustrated in FIG. 7P1A(c) and FIGS. 7P1B-7P1F. In oneembodiment, the aperture of the coupler 710 can be constructed of adielectric material (e.g., nylon, Teflon®, polyethylene, a polyamide, orother plastics). In other embodiments, the aperture of the coupler 710can be constructed of conducting traces, absorbing bands, or othermaterials that can modify an incoming electromagnetic wave entering thecoupler 710 from the backside 714 as illustrated in FIG. 7P4. It will beappreciated in other embodiments that the aperture of the coupler 710can be constructed from combinations of the foregoing materials and/orother materials described by the subject disclosure. The material of thecoupler 710 can be configured as concentric rings (712A through 712D)having different frontal widths defined by a plurality of radii (seeFIG. 7P3) and longitudinal depths (see FIG. 7P4), which can configurethe phases, amplitude, wavelength, and/or focus of the electromagneticwaves generated by each ring. For example, in an embodiment where thecoupler 710 is constructed of a dielectric material, when anelectromagnetic wave is supplied to the backside 714 of the aperture ofthe coupler 710, the variable depths (see FIG. 7P4) of the concentricrings (712A through 712D) can produce electromagnetic waves of differingphases. For instance, the electromagnetic wave produced by ring 712Aexperiences less delay than the wave produced by ring 712B, while thewave produced by ring 712B experience less delay than the wave producedby ring 712C, and so on. In this fashion, rings 712A through 712Ecollectively produce electromagnetic waves of differing phases.

It will be appreciated that in embodiments where one or more rings (712Athrough 712D) of the coupler 710 is constructed of a conducting orabsorbing material that the electromagnetic wave supplied to thebackside 714 of the coupler 710 can produce at the aperture of thecoupler 710 electromagnetic waves of differing amplitudes depending onthe conductive and/or absorbent properties of the rings. It will befurther appreciated that combinations of dielectric material andconducting or absorbent materials can be used to cause anelectromagnetic wave supplied to the backside 714 of the coupler 710 toproduce at the aperture of the coupler 710 electromagnetic waves ofdiffering amplitudes, phases, and/or wavelengths depending on theconductive and/or absorbent properties of the rings. The electromagneticwaves produced at the aperture of the coupler 170 can combine to producediffering wave modes that in combination result in a Bessel-likeelectromagnetic field structure.

The front view of the aperture of coupler 710 (see FIG. 7P3) illustratesrings that are configured with different frontal widths, which can bedefined by one or more radii. For example, the frontal width of ring712E can be defined by a first radius that extends to the outer edge ofthe wire 708, and a second radius that extends to the outer edge of ring712E. Similarly, the frontal width of ring 712D can be defined by afirst radius that extends to the outer edge of ring 712E, and a secondradius that extends to the outer edge of ring 712D. This same approachapplies to determining the frontal widths of rings 712A-712C. Theconfiguration of the variable frontal widths of the rings 712A-712Eenables focusing of the electromagnetic waves in a longitudinaldirection of the wire 708. The electromagnetic waves of differing phasescan produce a mixture of wave modes that combine into a resultingelectromagnetic wave having a desired depth of focus that produces aBessel-like electromagnetic field structure. The Bessel-like fieldstructure reduces the diffraction (leakage) of the resultingelectromagnetic wave as it propagates along the wire 708.

It will be appreciated that the aperture shown in FIGS. 7P3 and 7P4 canbe combined with the coupler of FIG. 7P1A(c) and FIGS. 7P1B-7P1F.Alternatively, the aperture shown in FIGS. 7P3 and 7P4 can be used witha tapered horn (not shown) having linear (metallic and/or dielectric)surfaces. It will be further appreciated that aperture shown in FIGS.7P3 and 7P4 can be combined with other waveguide structures in order toenable the generation of Bessel-like electromagnetic waves that reducediffraction of the wave as it propagates along a wire (or other physicaltransmission medium).

It will be further appreciated that the shape of the aperture of thecoupler 710 shown in FIGS. 7P3 and 7P4 can be modified in whole or inpart into other structural configurations that produce Bessel-likeelectromagnetic waves. For example, the edges of rings 712A through 712Ecan be curved or beveled to reduce sharp edges that can cause undesiredradiation and/or undesirable wave modes. In another embodiment, therings 712A-712E can be reconfigured to collectively form an aperturehaving a conical shape. In yet another embodiment, the backside 714 ofthe aperture of coupler 710 in whole or in part can be configured withone or more curved surfaces (e.g., convex or concave surface(s)) toconfigure the phases and focus of the electromagnetic waves generated byone or more rings 712A-712E.

It will be appreciated that the foregoing embodiments can be combined inwhole or in part to configure a coupler 710 that produceselectromagnetic waves having a Bessel-like field structure that reducesthe diffraction (leakage) of the resulting electromagnetic wave as itpropagates along the wire 708. It will be further appreciated that,singly or in combination, one or more of the embodiments of the couplerdescribed above can be configured to produce an electromagnetic wavehaving a transverse electromagnetic field configuration with a firstportion that has a field intensity greater than a second portion of theelectromagnetic field configuration. In this embodiment, the firstportion of the electromagnetic field configuration is positioned awayfrom an outer surface of the transmission medium (e.g., wire), while thesecond portion of the electromagnetic field configuration is lightlybound to the outer surface of the transmission medium to enable guidanceof the electromagnetic wave along the transmission medium. Having thefirst portion of the electromagnetic field configuration (which has thehigher field intensity) positioned away from the outer surface of thetransmission medium helps to substantially reduce a propagation lossexperienced by the electromagnetic wave when the transmission medium issubject to an obstruction (e.g., water film, water droplets, etc.)located on the outer surface of the transmission medium.

FIG. 7P5 illustrates a flow diagram of an example, non-limitingembodiment of a method 720 in accordance with various aspects describedherein. Method 720 can begin at step 722 where a transmitter (e.g., oneor more antennas) generates a signal (e.g., an electromagnetic wave).The signal can be configured to convey data (e.g., voice, internettraffic, streaming video, etc.). At step 724, a coupler such asdescribed in the subject disclosure (e.g., see FIGS. 7P1A-7P1F and7P2-7P4), can be configured to convert the signal into a plurality ofwave modes that combine at step 726 into an electromagnetic wave havingan electromagnetic field configuration that reduces diffraction(leakage) of the electromagnetic wave as it propagates and is guided atstep 728 by a transmission medium (e.g., a wire). In certainembodiments, the conversion can be performed by a circular horn having anon-linear profile that transforms the signal into the plurality of wavemodes.

The non-linear transformation can be performed by, for example, acoupler having a non-linear structural profile as illustrated by thehorn of FIG. 7P1A(c). Alternatively, an aperture such as shown in FIGS.7P3-7P4 can be used to generate a plurality of focused electromagneticwaves of varying phases with a depth of focus that increases aconcentration of electromagnetic fields of the electromagnetic wave, andthereby reduces a diffraction of the electromagnetic wave as itpropagates along the transmission medium. The aforementioned transmitterand coupler can be part of a waveguide system that includes a processingsystem with at least one processor, and a power supply (e.g., aninductive power supply that inductively obtains power from a wire) topower the components of the waveguide system.

In other embodiments, the aforementioned waveguide system can beconfigured to produce common electromagnetic waves (e.g., TM00 wave),which nonetheless, under favorable environmental conditions (e.g., a drywire), can propagate long distances on a physical transmission mediumsuch as a (bare or insulated) wire. When, for example, the environmentbecomes untenable for such waves to propagate long distances (e.g.,water accumulation on a wire), the waveguide system can be configured todetect at step 721 an interference that causes undesirable propagationlosses of the diffracting electromagnetic wave. Such detection can beperformed by receiving information from a recipient waveguide systemindicating signal degradation, exchanging test waves between pairs ofwaveguide systems coupled to the same span of a wire, measuringatmospheric conditions at a transmitting waveguide system, or othersuitable techniques. When such degradation is detected, a transmittingwaveguide system can be configured to transition from transmittingdiffracting electromagnetic waves to electromagnetic waves having anelectromagnetic field structure that reduces diffraction (or leakage) asdescribed by steps 722 through 728, and whose field structureconcentrates at least a majority of its energy away from the obstructioncausing the propagation losses.

Method 720 can be further adapted to receive at step 732 electromagneticwaves configured with an electromagnetic field structure that reducesdiffraction (or leakage) as described by steps 722 through 728. Theelectromagnetic waves can be received by the same or similar couplerdescribed by the subject disclosure (e.g., couplers of FIGS. 7P1A-7P1Fand 7P2-7P4). At step 734, the electromagnetic waves can be converted bythe coupler into a signal that conveys data, which can be extracted by areceiver at step 736. Pairs of waveguides that transmit or receiveelectromagnetic waves as described by method 720 can be configured withcircuitry such as shown in FIG. 4. The circuitry of FIG. 4 can befurther configured to also perform modulation and demodulation ofsignals as may be required.

While for purposes of simplicity of explanation, the respectiveprocesses are shown and described as a series of blocks in FIG. 7P5, itis to be understood and appreciated that the claimed subject matter isnot limited by the order of the blocks, as some blocks may occur indifferent orders and/or concurrently with other blocks from what isdepicted and described herein. Moreover, not all illustrated blocks maybe required to implement the methods described herein.

e) Measurement of Guidance on Curved Wires. When initially identifyingcandidate modes, simulations are performed with straight wires to takeadvantage of symmetry whether in eigenmode simulations with periodicboundary conditions or in driven modal frequency/time domain where wecan utilize fourfold symmetry. These simulations demonstrate guidance inthe presence of a wire for the Bessel-Gauss-like TM₁ mode as we do notobserve the modification of the transverse profile of the beam.

The principal concern for the accuracy of these simulations is theimpact of the absorbing boundary layer placed on the surface defined bythe fixed radius terminating the simulation domain. Extensive testingwas performed for validating these surfaces with various lengths andsimulation domains. When performing simulations with both the time andfrequency domain solvers and no wire we observe a divergence thatmatches the analytical prediction for a Bessel-Gauss beam, as shown inFIG. 7Q. This provides confirmation that our simulations are accurate.

When we are performing simulations with curved wires we utilize the timedomain solver in T3P because the curvature is very weak, requiring asignificant length for an effect to be observed. Initial benchmarking ofthese simulations was performed with the Sommerfeld mode, and we seestrong guidance without mode conversion (i.e., the normalized transversefield profile is constant).

The Bessel-Gauss-like TM modes that we have identified—which are asuperposition of guided modes—will inherently be more sensitive to thecurvature of the wire, due to the weaker currents on the surface of thewire relative to the power propagating in the mode. A lack of guidanceor a divergence in the power density of the beam in our simulationswould result in two effects: (i) a change in the transverse profile ofthe beam or mode conversion, and (ii) loss due to absorption at theradial boundaries.

To confirm guidance, we can look at the transverse field profile as itpropagates and also calculate the power flow with the Poynting vector.By exporting the electric and magnetic field at a transverse plane (X-Y)with respect to the direction of the wire (i.e., setting 2 along thecylindrical axis of the wire) we can observe both the transverse fieldprofile for evidence of mode conversion, as well as calculate thePoynting vector to observe the direction of power-flow. For the TM₁ modeat 25 GHz we have performed simulations that extend 20 m with atransverse displacement in the wire of >0.5 m, and we confirm low-loss˜−0.2 dB/m, no mode conversion (FIG. 7R), and that the power flow bothin aggregate (FIG. 7T) and locally (FIG. 7S) remains parallel to thedirection of the wire 2. It is worth noting that the transverse offsetis larger than the initial transverse extent of the simulation of 0.4 m.

f) Loss Calculations

i) Eigenmode simulations. For eigenmode simulations we are calculatingthe fields in a periodic domain with a forced set of boundaryconditions. For our simulations we utilize the {circumflex over (z)} asthe axis for the wire. The forced phase advance is between two x-ysurfaces separated by a sub-wavelength distance Δz. To calculate theloss per unit length we begin integrating the Poynting vector over thetransverse x-y plane to determine the power flowing in {circumflex over(z)} for the mode, P_(z). As a second step we integrate the powerdissipated on the conducting surface of the wire (I²R losses). As athird step we integrate the volumetric losses (tan δ). This includes thedielectric layer of water on the surface of the wire and the PMLboundary layer. The combined surface and volumetric losses correspond tothe total dissipated power P_(disp) in the differential element Δz. Tocalculate the loss per meter we set e^(−αΔz)=(1−Pdisp/Pz) and solvingfor α=−ln(1−Pdisp/Pz)/Δz[Np/m].

ii) Frequency Domain Driven Modal Simulations. The external fielddefined by its transverse distribution at a specific frequency is loadedat both the input and output ports. S3P is used for the S-Parametercalculation including S₀₀, S₁₁, S₀₁(=S₁₀), which are the reflectioncoefficients at the input and output ports, and the transmissioncoefficient from the input to output ports. The wire insertion loss iscalculated through the S-parameters byP_(loss)=10*log(S₀₁*S₀₁/(1−S₀₀*S₀₀)) to exclude the reflection loss atthe ports.

iii) Time Domain Simulations. The external field is excited at the inputport in a Gaussian pulse shape, which is defined by its mean frequencyand bandwidth. The external field is determined by its transversedistribution at the mean frequency. T3P can simulate the mode powerpropagation along the wire system. The power P_(in) and P_(out) at theinput and output ports, respectively, are calculated at each time step.An absorbing boundary condition is set at the downstream output port toterminate wave propagation. In addition, the reflection loss at theinput port is negligible compared with the loss on a long wire system.Therefore, the wire insertion loss in T3P is calculated byP_(loss)=10*log(P_(out)/P_(in)) by neglecting the reflection loss at theports (which would only decrease the amount of loss).

Low-Loss Propagation of Guided Waves on a Wire

The guided modes on the wire can be described using a basis set ofHankel functions. In order to control the loss from propagation we aimto control the field distribution on the wire through a superposition ofmultiple modes—which should work well at high frequency with lowdispersion—while localizing the field around the wire for good guidance.We found in our modeling that by forcing boundary conditions thatrequire fields to go to zero beyond a given radius, we could control thefield distribution and localize it to the vicinity of the wire. Thefields we observed were simple to describe with a Bessel-Gauss formalismbecause effectively there are fewer parameters—primarily two: the Besselindex and the beam waist. (see, for example, Hall, Dennis G.“Vector-beam solutions of Maxwell's wave equation.” Optics letters 21.1(1996): 9-11.).

These field distributions could also be described accurately with a sumof Bessel functions, but it would require many more parameters as manyBessel functions must be superimposed to force the fields to zero beyonda given radius. Our efforts have focused on investigating theBessel-Gauss TM₁ and TM₁₁ mode where the first subscript indicates theorder of the Bessel function and the second the number of radialvariations. These two modes exemplify some clear benefits. First, theTM₁ mode has a non-uniform field distribution which may prove beneficialin handling the presence of water droplets on the wire. Second, the TM₁₁mode has very weak fields on the wire surface, which are increased bythe presence of water providing additional guidance at the cost ofadditional ohmic loss. This mode is weakly impacted by water allowing usto reach higher in frequency but is more sensitive to bends and modeconversion. Field patterns for the modes with water are shown below, seeFIG. 7U.

a) Eigenmode Simulations—Periodic Straight Wire

Initial calculations of loss for the candidate TM₁ and TM₁₁ modes wereperformed with the eigenmode solver over a large frequency range. Theseresults indicate that the TM₁ and TM₁₁ solutions work well over twodifferent frequency ranges. One from 5-25 GHz for the TM₁ and one from30-65 GHz for the TM₁₁. Eigenmode simulations can produce very accurateresults for periodic simulations, but they require extremely densemeshes. This is due to the periodic nature of the problem, where anydefect (mesh quality at interface or impedance mismatch at PML) getsamplified. In FIGS. 7V, 7W and 7X we show the eigenmode simulationresults for the Bessel-Gauss-like modes in the presence of a water layerfor various modes, frequencies and with an insulator coating the wire.See Tables 6 and 7 for dielectric constants for water and insulatorcoatings.

TABLE 4 Dielectric Constant of Water vs. Frequency for Simulations.Freq. (GHz) ∈_(r) ∈_(i) σ (S/m) 5 73.5 17.7 4.9 10 63.0 29.6 16.5 1550.8 34.4 28.7 20 40.1 35.4 39.4 25 31.9 34.5 48.0 30 26.1 32.6 54.3 3522.0 30.3 58.9 40 19.0 28.2 62.7 45 16.7 26.3 65.7 50 15.0 24.5 68.2 5513.8 22.9 70.1 60 12.9 21.4 71.4 65 12.1 19.9 72.1 70 11.5 18.7 72.6 7510.7 17.6 73.3 80 9.9 16.7 74.3

TABLE 5 Dielectric Constant of Wire Coating Material ∈_(r) Loss TangentHDPE Plastic 2.3 0.0005

b) S3P Frequency Domain Simulations—Straight Wire

To verify the loss calculations of the eigenmode simulations, weperformed frequency domain simulations over straight wire sections forvarious modes at selected frequencies. Good agreement is observedbetween different approaches. An example of the simulation domain isshown in FIG. 7O. In Table 4 we present a combined summary of theseresults.

TABLE 6 Comparison between frequency domain simulation results for S3Pand eigenmode solver for a straight wire with 0.5 cm radius. S3PFrequency Domain Eigenmode Freq. Length Loss Loss Mode (GHz) Notes (m)(dB/m) (dB/m) TM₀ 5 1 −0.01 0.03 TM₀ 5 0.1 mm 0.5 −0.3 −0.1 Water FilmTM₀ 5 2 mm Insulator, 1 −1.6 −3.5 0.1 mm Water Film TM₀ 20 0.06 −0.1−0.06 TM₀ 20 0.1 mm 0.06 −1.4 −1.1 Water Film TM₁ 12.5 0.12 −0.07 −0.01TM₁ 12.5 0.1 mm 0.12 −0.05 −0.03 Water Film TM₁ 25 0.1 −0.04 −0.01 TM₁25 0.1 mm 0.1 −0.4 −0.35 Water Film TM₁₁ 36 0.1 mm 0.016 −0.023 −0.055Water Film TM₁₁ 57 0.1 mm 0.005 −0.028 −0.023 Water Film

Guided Mode Propagation Configured for Operation to SpecificGeometry(ies)

To further our investigation into the guidance of these modes weutilized T3P to perform FEM time domain simulations. By directlyexciting a particular field distribution onto the wire we can testpropagation and loss, see FIG. 7Y. We utilize the same fielddistribution for excitation as was used for the frequency domainsimulations in S3P. In the T3P simulations, we do see that these modesare guided along a wire. Table 5 presents a summarized list of thesimulations that have been performed along with some details on thesimulation parameters. Attenuation values for frequency domain drivenmodal and eigenmode simulations are listed for reference.

TABLE 7 Comparison between time domain simulation results for wire with0.5 cm radius in T3P with S3P and eigenmode solver for reference. S3PT3P Time Domain Frequency Eigenmode Freq. Length Loss Domain Loss Mode(GHz) Notes (m) (dB/m) Loss (dB/m) (dB/m) TM₀ 5 Straight 50 −0.08 −0.01−0.03 TM₀ 5 0.1 mm Water Film −0.3 −0.1 TM₀ 20 Straight −0.1 −0.06 TM₀20 0.1 mm Water Film −1.4 −1.1 TM₁ 5 0.1 mm Water Film −0.18 TM₁ 5Sag-0.1 mm Water 25 −0.52 Film TM₁ 12.5 Straight 10 −0.09* −0.07 −0.01TM₁ 12.5 0.1 mm Water Film 10 −0.05 −0.05 −0.03 TM₁ 12.5 Sag 10 −0.07*TM₁ 12.5 Sag 0.1 mm Water 25 −0.05 Film TM₁ 25 Straight −0.04 −0.01 TM₁25 0.1 mm Water Film −0.4 −0.35 TM₁ 25 Sag 5 −0.28* TM₁ 25 Sag-0.1 mmWater 20 −0.2 Film TM₁₁ 36 0.1 mm Water Film 0.1 −0.07 −0.023 −0.055TM₁₁ 57 0.1 mm Water Film −0.028 −0.023 TM₁₁ 36 Sag-0.1 mm Water 5−0.6^(#) Film TM₁₁ 57 Sag-0.1 mm Water 2 −2.5^(#) Film

Water Droplets. We have also initiated our investigation into the impactof water droplets on the wire, which we expect to be limited due to theazimuthal asymmetry of the mode. Water droplets that are 0.5 mm thickwere placed on a wire as shown in FIG. 7Z. For this simulation with theTM₁ at 12.5 GHz, there was no measurable increase in loss (−0.07 dB/m)or distortion to the field.

See also FIGS. 7AA-7AB. FIG. 7AA is a graphical diagram illustrating, anexample, non-limiting embodiment of (a) spectral amplitude comparedbetween input (blue) and out (red) pulse for a 1 ns 12.5 GHz TM₁ pulsefor at 25 m simulation on a 0.5 cm radius wire with 0.1 mm water film;and (b) Calculated loss from spectral attenuation for varioussimulations of the TM₁ mode in accordance with various aspects describedherein. FIG. 7AB is a graphical diagram illustrating, an example,non-limiting embodiment of dispersion as a function of frequencycalculated from a 25 GHz TM₁ pulse in a 10 m simulation on a 0.5 cmradius wire with a 0.1 mm water film after removing the constant phaseadvance from the group velocity of the pulse in accordance with variousaspects described herein.

It will be appreciated that the foregoing embodiments of the subjectdisclosure are not limited to a specific frequency, or frequency rangesas may be disclosed in the subject disclosure. It will also beappreciated that simulations described by the subject disclosure thatare configured at a particular frequency or ranges of frequencies areillustrative and non-limiting. Accordingly, the couplers described bythe subject disclosure can be configured to transmit and receiveelectromagnetic waves having the field structure described above atother operating frequencies not described in the subject disclosure.

It will be further appreciated that the foregoing embodiments of FIGS.1-6, and 7A through 7AB can be combined in whole or in part with oneanother, and/or can be combined in whole or in part with otherembodiments of the subject disclosure, and/or can be adapted for use inwhole or in part with other embodiments of the subject disclosure.

It is also appreciated that any of the embodiments of the subjectdisclosure (singly or in any combination) which are adaptable fortransmitting or receiving communication signals can be utilized asnetwork elements for the distribution and/or routing of media content,voice communications, video streaming, internet traffic or other datatransport. It is further appreciated that such network elements can beadapted or otherwise utilized in a communication network described belowin relation to FIG. 8 for the distribution or routing of media content,voice communications, video streaming, internet traffic or other datatransport. It is also appreciated that such network elements can also beconfigured to utilize virtualized communication network techniquesdescribed below in relation to FIG. 9.

Referring now to FIG. 8, a block diagram is shown illustrating anexample, non-limiting embodiment of a communications network 800 inaccordance with various aspects described herein. In particular, acommunications network 825 is presented for providing broadband access810 to a plurality of data terminals 814 via access terminal 812,wireless access 820 to a plurality of mobile devices 824 and vehicle 826via base station or access point 822, voice access 830 to a plurality oftelephony devices 834, via switching device 832 and/or media access 840to a plurality of audio/video display devices 844 via media terminal842. In addition, communication network 825 is coupled to one or morecontent sources 875 of audio, video, graphics, text and/or other media.While broadband access 810, wireless access 820, voice access 830 andmedia access 840 are shown separately, one or more of these forms ofaccess can be combined to provide multiple access services to a singleclient device (e.g., mobile devices 824 can receive media content viamedia terminal 842, data terminal 814 can be provided voice access viaswitching device 832, and so on).

The communications network 825 includes a plurality of network elements(NE) 850, 852, 854, 856, etc. for facilitating the broadband access 810,wireless access 820, voice access 830, media access 840 and/or thedistribution of content from content sources 875. The communicationsnetwork 825 can include a circuit switched or packet switched network, avoice over Internet protocol (VoIP) network, Internet protocol (IP)network, a cable network, a passive or active optical network, a 4G, 5G,or higher generation wireless access network, WIMAX network,UltraWideband network, personal area network or other wireless accessnetwork, a broadcast satellite network and/or other communicationsnetwork.

In various embodiments, the access terminal 812 can include a digitalsubscriber line access multiplexer (DSLAM), cable modem terminationsystem (CMTS), optical line terminal (OLT) and/or other access terminal.The data terminals 814 can include personal computers, laptop computers,netbook computers, tablets or other computing devices along with digitalsubscriber line (DSL) modems, data over coax service interfacespecification (DOCSIS) modems or other cable modems, a wireless modemsuch as a 4G, 5G, or higher generation modem, an optical modem and/orother access devices.

In various embodiments, the base station or access point 822 can includea 4G, 5G, or higher generation base station, an access point thatoperates via an 802.11 standard such as 802.11n, 802.11ac, 802.11ag,802.11agn or other wireless access terminal. The mobile devices 824 caninclude mobile phones, e-readers, tablets, phablets, wireless modems,and/or other mobile computing devices.

In various embodiments, the switching device 832 can include a privatebranch exchange or central office switch, a media services gateway, VoIPgateway or other gateway device and/or other switching device. Thetelephony devices 834 can include traditional telephones (with orwithout a terminal adapter), VoIP telephones and/or other telephonydevices.

In various embodiments, the media terminal 842 can include a cablehead-end or other TV head-end, a satellite receiver, gateway or othermedia terminal 842. The display devices 844 can include televisions withor without a set top box, personal computers and/or other displaydevices.

In various embodiments, the content sources 875 include broadcasttelevision and radio sources, video on demand platforms and streamingvideo and audio services platforms, one or more content data networks,data servers, web servers and other content servers, and/or othersources of media.

In various embodiments, the communications network 825 can includewired, optical and/or wireless links and the network elements 850, 852,854, 856, etc. can include service switching points, signal transferpoints, service control points, network gateways, media distributionhubs, servers, firewalls, routers, edge devices, switches and othernetwork nodes for routing and controlling communications traffic overwired, optical and wireless links as part of the Internet and otherpublic networks as well as one or more private networks, for managingsubscriber access, for billing and network management and for supportingother network functions.

It will be appreciated that any of the subsystems (e.g., access terminal812, network elements 850-856, media terminal 842, switching device 832,wireless access 820, and so on) of the communication network 800 can beconfigured or otherwise adapted to utilize in whole or in part any ofthe embodiments of the subject disclosure for transmitting and receivingcommunication signals via electromagnetic waves that propagate overwireless or physical transmission media.

Referring now to FIG. 9, a block diagram 900 is shown illustrating anexample, non-limiting embodiment of a virtualized communication networkin accordance with various aspects described herein. In particular avirtualized communication network is presented that can be used toimplement some or all of the subsystems and functions of communicationnetwork 800, some or all of the embodiments associated with waveguidesystems and methods thereof, some or all of the embodiments associatedwith distributed antenna systems, or other embodiments and methodsthereof described by the subject disclosure.

In particular, a cloud networking architecture is shown that leveragescloud technologies and supports rapid innovation and scalability via atransport layer 950, a virtualized network function cloud 925 and/or oneor more cloud computing environments 975. In various embodiments, thiscloud networking architecture is an open architecture that leveragesapplication programming interfaces (APIs); reduces complexity fromservices and operations; supports more nimble business models; andrapidly and seamlessly scales to meet evolving customer requirementsincluding traffic growth, diversity of traffic types, and diversity ofperformance and reliability expectations.

In contrast to traditional network elements—which are typicallyintegrated to perform a single function, the virtualized communicationnetwork employs virtual network elements 930, 932, 934, etc. thatperform some or all of the functions of network elements 850, 852, 854,856, etc. For example, the network architecture can provide a substrateof networking capability, often called Network Function VirtualizationInfrastructure (NFVI) or simply infrastructure that is capable of beingdirected with software and Software Defined Networking (SDN) protocolsto perform a broad variety of network functions and services. Thisinfrastructure can include several types of substrates. The most typicaltype of substrate being servers that support Network FunctionVirtualization (NFV), followed by packet forwarding capabilities basedon generic computing resources, with specialized network technologiesbrought to bear when general purpose processors or general purposeintegrated circuit devices offered by merchants (referred to herein asmerchant silicon) are not appropriate. In this case, communicationservices can be implemented as cloud-centric workloads.

As an example, a traditional network element 850 (shown in FIG. 8), suchas an edge router can be implemented via a virtual network element 930composed of NFV software modules, merchant silicon, and associatedcontrollers. The software can be written so that increasing workloadconsumes incremental resources from a common resource pool, and moreoverso that it's elastic: so the resources are only consumed when needed. Ina similar fashion, other network elements such as other routers,switches, edge caches, and middle-boxes are instantiated from the commonresource pool. Such sharing of infrastructure across a broad set of usesmakes planning and growing infrastructure easier to manage.

In an embodiment, the transport layer 950 includes fiber, cable, wiredand/or wireless transport elements, network elements and interfaces toprovide broadband access 810, wireless access 820, voice access 830,media access 840 and/or access to content sources 875 for distributionof content to any or all of the access technologies. In particular, insome cases a network element needs to be positioned at a specific place,and this allows for less sharing of common infrastructure. Other times,the network elements have specific physical layer adapters that cannotbe abstracted or virtualized, and might require special DSP code andanalog front-ends (AFEs) that do not lend themselves to implementationas virtual network elements 930, 932 or 934. These network elements canbe included in transport layer 950.

The virtualized network function cloud 925 interfaces with the transportlayer 950 to provide the virtual network elements 930, 932, 934, etc. toprovide specific NFVs. In particular, the virtualized network functioncloud 925 leverages cloud operations, applications, and architectures tosupport networking workloads. The virtualized network elements 930, 932and 934 can employ network function software that provides either aone-for-one mapping of traditional network element function oralternately some combination of network functions designed for cloudcomputing. For example, virtualized network elements 930, 932 and 934can include route reflectors, domain name system (DNS) servers, anddynamic host configuration protocol (DHCP) servers, system architectureevolution (SAE) and/or mobility management entity (MME) gateways,broadband network gateways, IP edge routers for IP-VPN, Ethernet andother services, load balancers, distributors and other network elements.Because these elements don't typically need to forward large amounts oftraffic, their workload can be distributed across a number ofservers—each of which adds a portion of the capability, and overallwhich creates an elastic function with higher availability than itsformer monolithic version. These virtual network elements 930, 932, 934,etc. can be instantiated and managed using an orchestration approachsimilar to those used in cloud compute services.

The cloud computing environments 975 can interface with the virtualizednetwork function cloud 925 via APIs that expose functional capabilitiesof the VNE 930, 932, 934, etc. to provide the flexible and expandedcapabilities to the virtualized network function cloud 925. Inparticular, network workloads may have applications distributed acrossthe virtualized network function cloud 925 and cloud computingenvironment 975 and in the commercial cloud, or might simply orchestrateworkloads supported entirely in NFV infrastructure from these thirdparty locations.

It will be appreciated that any of the foregoing techniques can beapplied or combined in whole or in party with any embodiments of thesubsystems and functions of communication network 800, some or all ofthe embodiments associated with waveguide systems and methods thereof,some or all of the embodiments associated with distributed antennasystems, as well as other embodiments and methods thereof described bythe subject disclosure.

Referring now to FIG. 10, there is illustrated a block diagram of acomputing environment in accordance with various aspects describedherein. In order to provide additional context for various embodimentsof the embodiments described herein, FIG. 10 and the followingdiscussion are intended to provide a brief, general description of asuitable computing environment 1000 in which the various embodiments ofthe subject disclosure can be implemented. While the embodiments havebeen described above in the general context of computer-executableinstructions that can run on one or more computers, those skilled in theart will recognize that the embodiments can be also implemented incombination with other program modules and/or as a combination ofhardware and software.

Generally, program modules comprise routines, programs, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Moreover, those skilled in the art will appreciatethat the inventive methods can be practiced with other computer systemconfigurations, comprising single-processor or multiprocessor computersystems, minicomputers, mainframe computers, as well as personalcomputers, hand-held computing devices, microprocessor-based orprogrammable consumer electronics, and the like, each of which can beoperatively coupled to one or more associated devices.

As used herein, a processing circuit includes processor as well as otherapplication specific circuits such as an application specific integratedcircuit, digital logic circuit, state machine, programmable gate arrayor other circuit that processes input signals or data and that producesoutput signals or data in response thereto. It should be noted thatwhile any functions and features described herein in association withthe operation of a processor could likewise be performed by a processingcircuit.

The terms “first,” “second,” “third,” and so forth, as used in theclaims, unless otherwise clear by context, is for clarity only anddoesn't otherwise indicate or imply any order in time. For instance, “afirst determination,” “a second determination,” and “a thirddetermination,” does not indicate or imply that the first determinationis to be made before the second determination, or vice versa, etc.

The illustrated embodiments of the embodiments herein can be alsopracticed in distributed computing environments where certain tasks areperformed by remote processing devices that are linked through acommunications network. In a distributed computing environment, programmodules can be located in both local and remote memory storage devices.

Computing devices typically comprise a variety of media, which cancomprise computer-readable storage media and/or communications media,which two terms are used herein differently from one another as follows.Computer-readable storage media can be any available storage media thatcan be accessed by the computer and comprises both volatile andnonvolatile media, removable and non-removable media. By way of example,and not limitation, computer-readable storage media can be implementedin connection with any method or technology for storage of informationsuch as computer-readable instructions, program modules, structured dataor unstructured data.

Computer-readable storage media can comprise, but are not limited to,random access memory (RAM), read only memory (ROM), electricallyerasable programmable read only memory (EEPROM),flash memory or othermemory technology, compact disk read only memory (CD-ROM), digitalversatile disk (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devicesor other tangible and/or non-transitory media which can be used to storedesired information. In this regard, the terms “tangible” or“non-transitory” herein as applied to storage, memory orcomputer-readable media, are to be understood to exclude onlypropagating transitory signals per se as modifiers and do not relinquishrights to all standard storage, memory or computer-readable media thatare not only propagating transitory signals per se.

Computer-readable storage media can be accessed by one or more local orremote computing devices, e.g., via access requests, queries or otherdata retrieval protocols, for a variety of operations with respect tothe information stored by the medium.

Communications media typically embody computer-readable instructions,data structures, program modules or other structured or unstructureddata in a data signal such as a modulated data signal, e.g., a carrierwave or other transport mechanism, and comprises any informationdelivery or transport media. The term “modulated data signal” or signalsrefers to a signal that has one or more of its characteristics set orchanged in such a manner as to encode information in one or moresignals. By way of example, and not limitation, communication mediacomprise wired media, such as a wired network or direct-wiredconnection, and wireless media such as acoustic, RF, infrared and otherwireless media.

With reference again to FIG. 10, the example environment 1000 fortransmitting and receiving signals via or forming at least part of abase station (e.g., base station devices 304, macrocell site 302) orcentral office (e.g., central office 301). At least a portion of theexample environment 1000 can also be used for transmission devices 101or 102. The example environment can comprise a computer 1002, thecomputer 1002 comprising a processing unit 1004, a system memory 1006and a system bus 1008. The system bus 1008 couple's system componentsincluding, but not limited to, the system memory 1006 to the processingunit 1004. The processing unit 1004 can be any of various commerciallyavailable processors. Dual microprocessors and other multiprocessorarchitectures can also be employed as the processing unit 1004.

The system bus 1008 can be any of several types of bus structure thatcan further interconnect to a memory bus (with or without a memorycontroller), a peripheral bus, and a local bus using any of a variety ofcommercially available bus architectures. The system memory 1006comprises ROM 1010 and RAM 1012. A basic input/output system (BIOS) canbe stored in a non-volatile memory such as ROM, erasable programmableread only memory (EPROM), EEPROM, which BIOS contains the basic routinesthat help to transfer information between elements within the computer1002, such as during startup. The RAM 1012 can also comprise ahigh-speed RAM such as static RAM for caching data.

The computer 1002 further comprises an internal hard disk drive (HDD)1014 (e.g., EIDE, SATA), which internal hard disk drive 1014 can also beconfigured for external use in a suitable chassis (not shown), amagnetic floppy disk drive (FDD) 1016, (e.g., to read from or write to aremovable diskette 1018) and an optical disk drive 1020, (e.g., readinga CD-ROM disk 1022 or, to read from or write to other high capacityoptical media such as the DVD). The hard disk drive 1014, magnetic diskdrive 1016 and optical disk drive 1020 can be connected to the systembus 1008 by a hard disk drive interface 1024, a magnetic disk driveinterface 1026 and an optical drive interface 1028, respectively. Theinterface 1024 for external drive implementations comprises at least oneor both of Universal Serial Bus (USB) and Institute of Electrical andElectronics Engineers (IEEE) 1394 interface technologies. Other externaldrive connection technologies are within contemplation of theembodiments described herein.

The drives and their associated computer-readable storage media providenonvolatile storage of data, data structures, computer-executableinstructions, and so forth. For the computer 1002, the drives andstorage media accommodate the storage of any data in a suitable digitalformat. Although the description of computer-readable storage mediaabove refers to a hard disk drive (HDD), a removable magnetic diskette,and a removable optical media such as a CD or DVD, it should beappreciated by those skilled in the art that other types of storagemedia which are readable by a computer, such as zip drives, magneticcassettes, flash memory cards, cartridges, and the like, can also beused in the example operating environment, and further, that any suchstorage media can contain computer-executable instructions forperforming the methods described herein.

A number of program modules can be stored in the drives and RAM 1012,comprising an operating system 1030, one or more application programs1032, other program modules 1034 and program data 1036. All or portionsof the operating system, applications, modules, and/or data can also becached in the RAM 1012. The systems and methods described herein can beimplemented utilizing various commercially available operating systemsor combinations of operating systems. Examples of application programs1032 that can be implemented and otherwise executed by processing unit1004 include the diversity selection determining performed bytransmission device 101 or 102.

A user can enter commands and information into the computer 1002 throughone or more wired/wireless input devices, e.g., a keyboard 1038 and apointing device, such as a mouse 1040. Other input devices (not shown)can comprise a microphone, an infrared (IR) remote control, a joystick,a game pad, a stylus pen, touch screen or the like. These and otherinput devices are often connected to the processing unit 1004 through aninput device interface 1042 that can be coupled to the system bus 1008,but can be connected by other interfaces, such as a parallel port, anIEEE 1394 serial port, a game port, a universal serial bus (USB) port,an IR interface, etc.

A monitor 1044 or other type of display device can be also connected tothe system bus 1008 via an interface, such as a video adapter 1046. Itwill also be appreciated that in alternative embodiments, a monitor 1044can also be any display device (e.g., another computer having a display,a smart phone, a tablet computer, etc.) for receiving displayinformation associated with computer 1002 via any communication means,including via the Internet and cloud-based networks. In addition to themonitor 1044, a computer typically comprises other peripheral outputdevices (not shown), such as speakers, printers, etc.

The computer 1002 can operate in a networked environment using logicalconnections via wired and/or wireless communications to one or moreremote computers, such as a remote computer(s) 1048. The remotecomputer(s) 1048 can be a workstation, a server computer, a router, apersonal computer, portable computer, microprocessor-based entertainmentappliance, a peer device or other common network node, and typicallycomprises many or all of the elements described relative to the computer1002, although, for purposes of brevity, only a memory/storage device1050 is illustrated. The logical connections depicted comprisewired/wireless connectivity to a local area network (LAN) 1052 and/orlarger networks, e.g., a wide area network (WAN) 1054. Such LAN and WANnetworking environments are commonplace in offices and companies, andfacilitate enterprise-wide computer networks, such as intranets, all ofwhich can connect to a global communications network, e.g., theInternet.

When used in a LAN networking environment, the computer 1002 can beconnected to the local network 1052 through a wired and/or wirelesscommunication network interface or adapter 1056. The adapter 1056 canfacilitate wired or wireless communication to the LAN 1052, which canalso comprise a wireless AP disposed thereon for communicating with thewireless adapter 1056.

When used in a WAN networking environment, the computer 1002 cancomprise a modem 1058 or can be connected to a communications server onthe WAN 1054 or has other means for establishing communications over theWAN 1054, such as by way of the Internet. The modem 1058, which can beinternal or external and a wired or wireless device, can be connected tothe system bus 1008 via the input device interface 1042. In a networkedenvironment, program modules depicted relative to the computer 1002 orportions thereof, can be stored in the remote memory/storage device1050. It will be appreciated that the network connections shown areexample and other means of establishing a communications link betweenthe computers can be used.

The computer 1002 can be operable to communicate with any wirelessdevices or entities operatively disposed in wireless communication,e.g., a printer, scanner, desktop and/or portable computer, portabledata assistant, communications satellite, any piece of equipment orlocation associated with a wirelessly detectable tag (e.g., a kiosk,news stand, restroom), and telephone. This can comprise WirelessFidelity (Wi-Fi) and Bluetooth® wireless technologies. Thus, thecommunication can be a predefined structure as with a conventionalnetwork or simply an ad hoc communication between at least two devices.

Wi-Fi can allow connection to the Internet from a couch at home, a bedin a hotel room or a conference room at work, without wires. Wi-Fi is awireless technology similar to that used in a cell phone that enablessuch devices, e.g., computers, to send and receive data indoors and out;anywhere within the range of a base station. Wi-Fi networks use radiotechnologies called IEEE 802.11 (a, b, g, n, ac, ag etc.) to providesecure, reliable, fast wireless connectivity. A Wi-Fi network can beused to connect computers to each other, to the Internet, and to wirednetworks (which can use IEEE 802.3 or Ethernet). Wi-Fi networks operatein the unlicensed 2.4 and 5 GHz radio bands for example or with productsthat contain both bands (dual band), so the networks can providereal-world performance similar to the basic 10 BaseT wired Ethernetnetworks used in many offices.

FIG. 11 presents an example embodiment 1100 of a mobile network platform1110 that can implement and exploit one or more aspects of the disclosedsubject matter described herein. In one or more embodiments, the mobilenetwork platform 1110 can generate and receive signals transmitted andreceived by base stations (e.g., base station devices 304, macrocellsite 302), central office (e.g., central office 301), or transmissiondevice 101 or 102 associated with the disclosed subject matter.Generally, wireless network platform 1110 can comprise components, e.g.,nodes, gateways, interfaces, servers, or disparate platforms, thatfacilitate both packet-switched (PS) (e.g., internet protocol (IP),frame relay, asynchronous transfer mode (ATM)) and circuit-switched (CS)traffic (e.g., voice and data), as well as control generation fornetworked wireless telecommunication. As a non-limiting example,wireless network platform 1110 can be included in telecommunicationscarrier networks, and can be considered carrier-side components asdiscussed elsewhere herein. Mobile network platform 1110 comprises CSgateway node(s) 1122 which can interface CS traffic received from legacynetworks like telephony network(s) 1140 (e.g., public switched telephonenetwork (PSTN), or public land mobile network (PLMN)) or a signalingsystem #7 (SS7) network 1160. Circuit switched gateway node(s) 1122 canauthorize and authenticate traffic (e.g., voice) arising from suchnetworks. Additionally, CS gateway node(s) 1122 can access mobility, orroaming, data generated through SS7 network 1160; for instance, mobilitydata stored in a visited location register (VLR), which can reside inmemory 1130. Moreover, CS gateway node(s) 1122 interfaces CS-basedtraffic and signaling and PS gateway node(s) 1118. As an example, in a3GPP UMTS network, CS gateway node(s) 1122 can be realized at least inpart in gateway GPRS support node(s) (GGSN). It should be appreciatedthat functionality and specific operation of CS gateway node(s) 1122, PSgateway node(s) 1118, and serving node(s) 1116, is provided and dictatedby radio technology(ies) utilized by mobile network platform 1110 fortelecommunication.

In addition to receiving and processing CS-switched traffic andsignaling, PS gateway node(s) 1118 can authorize and authenticatePS-based data sessions with served mobile devices. Data sessions cancomprise traffic, or content(s), exchanged with networks external to thewireless network platform 1110, like wide area network(s) (WANs) 1150,enterprise network(s) 1170, and service network(s) 1180, which can beembodied in local area network(s) (LANs), can also be interfaced withmobile network platform 1110 through PS gateway node(s) 1118. It is tobe noted that WANs 1150 and enterprise network(s) 1170 can embody, atleast in part, a service network(s) like IP multimedia subsystem (IMS).Based on radio technology layer(s) available in technology resource(s)1117, packet-switched gateway node(s) 1118 can generate packet dataprotocol contexts when a data session is established; other datastructures that facilitate routing of packetized data also can begenerated. To that end, in an aspect, PS gateway node(s) 1118 cancomprise a tunnel interface (e.g., tunnel termination gateway (TTG) in3GPP UMTS network(s) (not shown)) which can facilitate packetizedcommunication with disparate wireless network(s), such as Wi-Finetworks.

In embodiment 1100, wireless network platform 1110 also comprisesserving node(s) 1116 that, based upon available radio technologylayer(s), convey the various packetized flows of data streams receivedthrough PS gateway node(s) 1118. It is to be noted that for technologyresource(s) 1117 that rely primarily on CS communication, server node(s)can deliver traffic without reliance on PS gateway node(s) 1118; forexample, server node(s) can embody at least in part a mobile switchingcenter. As an example, in a 3GPP UMTS network, serving node(s) 1116 canbe embodied in serving GPRS support node(s) (SGSN).

For radio technologies that exploit packetized communication, server(s)1114 in wireless network platform 1110 can execute numerous applicationsthat can generate multiple disparate packetized data streams or flows,and manage (e.g., schedule, queue, format . . . ) such flows. Suchapplication(s) can comprise add-on features to standard services (forexample, provisioning, billing, customer support . . . ) provided bywireless network platform 1110. Data streams (e.g., content(s) that arepart of a voice call or data session) can be conveyed to PS gatewaynode(s) 1118 for authorization/authentication and initiation of a datasession, and to serving node(s) 1116 for communication thereafter. Inaddition to application server, server(s) 1114 can comprise utilityserver(s), a utility server can comprise a provisioning server, anoperations and maintenance server, a security server that can implementat least in part a certificate authority and firewalls as well as othersecurity mechanisms, and the like. In an aspect, security server(s)secure communication served through wireless network platform 1110 toensure network's operation and data integrity in addition toauthorization and authentication procedures that CS gateway node(s) 1122and PS gateway node(s) 1118 can enact. Moreover, provisioning server(s)can provision services from external network(s) like networks operatedby a disparate service provider; for instance, WAN 1150 or GlobalPositioning System (GPS) network(s) (not shown). Provisioning server(s)can also provision coverage through networks associated to wirelessnetwork platform 1110 (e.g., deployed and operated by the same serviceprovider), such as the distributed antennas networks shown in FIG. 1that enhance wireless service coverage by providing more networkcoverage.

It is to be noted that server(s) 1114 can comprise one or moreprocessors configured to confer at least in part the functionality ofmacro network platform 1110. To that end, the one or more processor canexecute code instructions stored in memory 1130, for example. It isshould be appreciated that server(s) 1114 can comprise a contentmanager, which operates in substantially the same manner as describedhereinbefore.

In example embodiment 1100, memory 1130 can store information related tooperation of wireless network platform 1110. Other operationalinformation can comprise provisioning information of mobile devicesserved through wireless platform network 1110, subscriber databases;application intelligence, pricing schemes, e.g., promotional rates,flat-rate programs, couponing campaigns; technical specification(s)consistent with telecommunication protocols for operation of disparateradio, or wireless, technology layers; and so forth. Memory 1130 canalso store information from at least one of telephony network(s) 1140,WAN 1150, enterprise network(s) 1170, or SS7 network 1160. In an aspect,memory 1130 can be, for example, accessed as part of a data storecomponent or as a remotely connected memory store.

In order to provide a context for the various aspects of the disclosedsubject matter, FIG. 11, and the following discussion, are intended toprovide a brief, general description of a suitable environment in whichthe various aspects of the disclosed subject matter can be implemented.While the subject matter has been described above in the general contextof computer-executable instructions of a computer program that runs on acomputer and/or computers, those skilled in the art will recognize thatthe disclosed subject matter also can be implemented in combination withother program modules. Generally, program modules comprise routines,programs, components, data structures, etc. that perform particulartasks and/or implement particular abstract data types.

FIG. 12 depicts an illustrative embodiment of a communication device1200. The communication device 1200 can serve as an illustrativeembodiment of devices such as mobile devices and in-building devicesreferred to by the subject disclosure (e.g., in FIGS. 3 and 5A-5B).

The communication device 1200 can comprise a wireline and/or wirelesstransceiver 1202 (herein transceiver 1202), a user interface (UI) 1204,a power supply 1214, a location receiver 1216, a motion sensor 1218, anorientation sensor 1220, and a controller 1206 for managing operationsthereof. The transceiver 1202 can support short-range or long-rangewireless access technologies such as Bluetooth®, ZigBee®, WiFi, DECT, orcellular communication technologies, just to mention a few (Bluetooth®and ZigBee® are trademarks registered by the Bluetooth® Special InterestGroup and the ZigBee® Alliance, respectively). Cellular technologies caninclude, for example, CDMA-1X, UMTS/HSDPA, GSM/GPRS, TDMA/EDGE, EV/DO,WiMAX, SDR, LTE, as well as other next generation wireless communicationtechnologies as they arise. The transceiver 1202 can also be adapted tosupport circuit-switched wireline access technologies (such as PSTN),packet-switched wireline access technologies (such as TCP/IP, VoIP,etc.), and combinations thereof.

The UI 1204 can include a depressible or touch-sensitive keypad 1208with a navigation mechanism such as a roller ball, a joystick, a mouse,or a navigation disk for manipulating operations of the communicationdevice 1200. The keypad 1208 can be an integral part of a housingassembly of the communication device 1200 or an independent deviceoperably coupled thereto by a tethered wireline interface (such as a USBcable) or a wireless interface supporting for example Bluetooth®. Thekeypad 1208 can represent a numeric keypad commonly used by phones,and/or a QWERTY keypad with alphanumeric keys. The UI 1204 can furtherinclude a display 1210 such as monochrome or color LCD (Liquid CrystalDisplay), OLED (Organic Light Emitting Diode) or other suitable displaytechnology for conveying images to an end user of the communicationdevice 1200. In an embodiment where the display 1210 is touch-sensitive,a portion or all of the keypad 1208 can be presented by way of thedisplay 1210 with navigation features.

The display 1210 can use touch screen technology to also serve as a userinterface for detecting user input. As a touch screen display, thecommunication device 1200 can be adapted to present a user interfacehaving graphical user interface (GUI) elements that can be selected by auser with a touch of a finger. The touch screen display 1210 can beequipped with capacitive, resistive or other forms of sensing technologyto detect how much surface area of a user's finger has been placed on aportion of the touch screen display. This sensing information can beused to control the manipulation of the GUI elements or other functionsof the user interface. The display 1210 can be an integral part of thehousing assembly of the communication device 1200 or an independentdevice communicatively coupled thereto by a tethered wireline interface(such as a cable) or a wireless interface.

The UI 1204 can also include an audio system 1212 that utilizes audiotechnology for conveying low volume audio (such as audio heard inproximity of a human ear) and high volume audio (such as speakerphonefor hands free operation). The audio system 1212 can further include amicrophone for receiving audible signals of an end user. The audiosystem 1212 can also be used for voice recognition applications. The UI1204 can further include an image sensor 1213 such as a charged coupleddevice (CCD) camera for capturing still or moving images.

The power supply 1214 can utilize common power management technologiessuch as replaceable and rechargeable batteries, supply regulationtechnologies, and/or charging system technologies for supplying energyto the components of the communication device 1200 to facilitatelong-range or short-range portable communications. Alternatively, or incombination, the charging system can utilize external power sources suchas DC power supplied over a physical interface such as a USB port orother suitable tethering technologies.

The location receiver 1216 can utilize location technology such as aglobal positioning system (GPS) receiver capable of assisted GPS foridentifying a location of the communication device 1200 based on signalsgenerated by a constellation of GPS satellites, which can be used forfacilitating location services such as navigation. The motion sensor1218 can utilize motion sensing technology such as an accelerometer, agyroscope, or other suitable motion sensing technology to detect motionof the communication device 1200 in three-dimensional space. Theorientation sensor 1220 can utilize orientation sensing technology suchas a magnetometer to detect the orientation of the communication device1200 (north, south, west, and east, as well as combined orientations indegrees, minutes, or other suitable orientation metrics).

The communication device 1200 can use the transceiver 1202 to alsodetermine a proximity to a cellular, WiFi, Bluetooth®, or other wirelessaccess points by sensing techniques such as utilizing a received signalstrength indicator (RSSI) and/or signal time of arrival (TOA) or time offlight (TOF) measurements. The controller 1206 can utilize computingtechnologies such as a microprocessor, a digital signal processor (DSP),programmable gate arrays, application specific integrated circuits,and/or a video processor with associated storage memory such as Flash,ROM, RAM, SRAM, DRAM or other storage technologies for executingcomputer instructions, controlling, and processing data supplied by theaforementioned components of the communication device 1200.

Other components not shown in FIG. 12 can be used in one or moreembodiments of the subject disclosure. For instance, the communicationdevice 1200 can include a slot for adding or removing an identity modulesuch as a Subscriber Identity Module (SIM) card or Universal IntegratedCircuit Card (UICC). SIM or UICC cards can be used for identifyingsubscriber services, executing programs, storing subscriber data, and soon.

In the subject specification, terms such as “store,” “storage,” “datastore,” data storage,” “database,” and substantially any otherinformation storage component relevant to operation and functionality ofa component, refer to “memory components,” or entities embodied in a“memory” or components comprising the memory. It will be appreciatedthat the memory components described herein can be either volatilememory or nonvolatile memory, or can comprise both volatile andnonvolatile memory, by way of illustration, and not limitation, volatilememory, non-volatile memory, disk storage, and memory storage. Further,nonvolatile memory can be included in read only memory (ROM),programmable ROM (PROM), electrically programmable ROM (EPROM),electrically erasable ROM (EEPROM), or flash memory. Volatile memory cancomprise random access memory (RAM), which acts as external cachememory. By way of illustration and not limitation, RAM is available inmany forms such as synchronous RAM (SRAM), dynamic RAM (DRAM),synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhancedSDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).Additionally, the disclosed memory components of systems or methodsherein are intended to comprise, without being limited to comprising,these and any other suitable types of memory.

Moreover, it will be noted that the disclosed subject matter can bepracticed with other computer system configurations, comprisingsingle-processor or multiprocessor computer systems, mini-computingdevices, mainframe computers, as well as personal computers, hand-heldcomputing devices (e.g., PDA, phone, smartphone, watch, tabletcomputers, netbook computers, etc.), microprocessor-based orprogrammable consumer or industrial electronics, and the like. Theillustrated aspects can also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network; however, some if not allaspects of the subject disclosure can be practiced on stand-alonecomputers. In a distributed computing environment, program modules canbe located in both local and remote memory storage devices.

Some of the embodiments described herein can also employ artificialintelligence (AI) to facilitate automating one or more featuresdescribed herein. For example, artificial intelligence can be used inoptional training controller 230 evaluate and select candidatefrequencies, modulation schemes, MIMO modes, and/or guided wave modes inorder to maximize transfer efficiency. The embodiments (e.g., inconnection with automatically identifying acquired cell sites thatprovide a maximum value/benefit after addition to an existingcommunication network) can employ various AI-based schemes for carryingout various embodiments thereof. Moreover, the classifier can beemployed to determine a ranking or priority of the each cell site of theacquired network. A classifier is a function that maps an inputattribute vector, x=(x1, x2, x3, x4, . . . , xn), to a confidence thatthe input belongs to a class, that is, f(x)=confidence (class). Suchclassification can employ a probabilistic and/or statistical-basedanalysis (e.g., factoring into the analysis utilities and costs) toprognose or infer an action that a user desires to be automaticallyperformed. A support vector machine (SVM) is an example of a classifierthat can be employed. The SVM operates by finding a hypersurface in thespace of possible inputs, which the hypersurface attempts to split thetriggering criteria from the non-triggering events. Intuitively, thismakes the classification correct for testing data that is near, but notidentical to training data. Other directed and undirected modelclassification approaches comprise, e.g., naïve Bayes, Bayesiannetworks, decision trees, neural networks, fuzzy logic models, andprobabilistic classification models providing different patterns ofindependence can be employed. Classification as used herein also isinclusive of statistical regression that is utilized to develop modelsof priority.

As will be readily appreciated, one or more of the embodiments canemploy classifiers that are explicitly trained (e.g., via a generictraining data) as well as implicitly trained (e.g., via observing UEbehavior, operator preferences, historical information, receivingextrinsic information). For example, SVMs can be configured via alearning or training phase within a classifier constructor and featureselection module. Thus, the classifier(s) can be used to automaticallylearn and perform a number of functions, including but not limited todetermining according to a predetermined criteria which of the acquiredcell sites will benefit a maximum number of subscribers and/or which ofthe acquired cell sites will add minimum value to the existingcommunication network coverage, etc.

As used in some contexts in this application, in some embodiments, theterms “component,” “system” and the like are intended to refer to, orcomprise, a computer-related entity or an entity related to anoperational apparatus with one or more specific functionalities, whereinthe entity can be either hardware, a combination of hardware andsoftware, software, or software in execution. As an example, a componentmay be, but is not limited to being, a process running on a processor, aprocessor, an object, an executable, a thread of execution,computer-executable instructions, a program, and/or a computer. By wayof illustration and not limitation, both an application running on aserver and the server can be a component. One or more components mayreside within a process and/or thread of execution and a component maybe localized on one computer and/or distributed between two or morecomputers. In addition, these components can execute from variouscomputer readable media having various data structures stored thereon.The components may communicate via local and/or remote processes such asin accordance with a signal having one or more data packets (e.g., datafrom one component interacting with another component in a local system,distributed system, and/or across a network such as the Internet withother systems via the signal). As another example, a component can be anapparatus with specific functionality provided by mechanical partsoperated by electric or electronic circuitry, which is operated by asoftware or firmware application executed by a processor, wherein theprocessor can be internal or external to the apparatus and executes atleast a part of the software or firmware application. As yet anotherexample, a component can be an apparatus that provides specificfunctionality through electronic components without mechanical parts,the electronic components can comprise a processor therein to executesoftware or firmware that confers at least in part the functionality ofthe electronic components. While various components have beenillustrated as separate components, it will be appreciated that multiplecomponents can be implemented as a single component, or a singlecomponent can be implemented as multiple components, without departingfrom example embodiments.

Further, the various embodiments can be implemented as a method,apparatus or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware or anycombination thereof to control a computer to implement the disclosedsubject matter. The term “article of manufacture” as used herein isintended to encompass a computer program accessible from anycomputer-readable device or computer-readable storage/communicationsmedia. For example, computer readable storage media can include, but arenot limited to, magnetic storage devices (e.g., hard disk, floppy disk,magnetic strips), optical disks (e.g., compact disk (CD), digitalversatile disk (DVD)), smart cards, and flash memory devices (e.g.,card, stick, key drive). Of course, those skilled in the art willrecognize many modifications can be made to this configuration withoutdeparting from the scope or spirit of the various embodiments.

In addition, the words “example” and “exemplary” are used herein to meanserving as an instance or illustration. Any embodiment or designdescribed herein as “example” or “exemplary” is not necessarily to beconstrued as preferred or advantageous over other embodiments ordesigns. Rather, use of the word example or exemplary is intended topresent concepts in a concrete fashion. As used in this application, theterm “or” is intended to mean an inclusive “or” rather than an exclusive“or”. That is, unless specified otherwise or clear from context, “Xemploys A or B” is intended to mean any of the natural inclusivepermutations. That is, if X employs A; X employs B; or X employs both Aand B, then “X employs A or B” is satisfied under any of the foregoinginstances. In addition, the articles “a” and “an” as used in thisapplication and the appended claims should generally be construed tomean “one or more” unless specified otherwise or clear from context tobe directed to a singular form.

Moreover, terms such as “user equipment,” “mobile station,” “mobile,”subscriber station,” “access terminal,” “terminal,” “handset,” “mobiledevice” (and/or terms representing similar terminology) can refer to awireless device utilized by a subscriber or user of a wirelesscommunication service to receive or convey data, control, voice, video,sound, gaming or substantially any data-stream or signaling-stream. Theforegoing terms are utilized interchangeably herein and with referenceto the related drawings.

Furthermore, the terms “user,” “subscriber,” “customer,” “consumer” andthe like are employed interchangeably throughout, unless contextwarrants particular distinctions among the terms. It should beappreciated that such terms can refer to human entities or automatedcomponents supported through artificial intelligence (e.g., a capacityto make inference based, at least, on complex mathematical formalisms),which can provide simulated vision, sound recognition and so forth.

As employed herein, the term “processor” can refer to substantially anycomputing processing unit or device comprising, but not limited tocomprising, single-core processors; single-processors with softwaremultithread execution capability; multi-core processors; multi-coreprocessors with software multithread execution capability; multi-coreprocessors with hardware multithread technology; parallel platforms; andparallel platforms with distributed shared memory. Additionally, aprocessor can refer to an integrated circuit, an application specificintegrated circuit (ASIC), a digital signal processor (DSP), a fieldprogrammable gate array (FPGA), a programmable logic controller (PLC), acomplex programmable logic device (CPLD), a discrete gate or transistorlogic, discrete hardware components or any combination thereof designedto perform the functions described herein. Processors can exploitnano-scale architectures such as, but not limited to, molecular andquantum-dot based transistors, switches and gates, in order to optimizespace usage or enhance performance of user equipment. A processor canalso be implemented as a combination of computing processing units.

As used herein, terms such as “data storage,” data storage,” “database,”and substantially any other information storage component relevant tooperation and functionality of a component, refer to “memorycomponents,” or entities embodied in a “memory” or components comprisingthe memory. It will be appreciated that the memory components orcomputer-readable storage media, described herein can be either volatilememory or nonvolatile memory or can include both volatile andnonvolatile memory.

What has been described above includes mere examples of variousembodiments. It is, of course, not possible to describe everyconceivable combination of components or methodologies for purposes ofdescribing these examples, but one of ordinary skill in the art canrecognize that many further combinations and permutations of the presentembodiments are possible. Accordingly, the embodiments disclosed and/orclaimed herein are intended to embrace all such alterations,modifications and variations that fall within the spirit and scope ofthe appended claims. Furthermore, to the extent that the term “includes”is used in either the detailed description or the claims, such term isintended to be inclusive in a manner similar to the term “comprising” as“comprising” is interpreted when employed as a transitional word in aclaim.

In addition, a flow diagram may include a “start” and/or “continue”indication. The “start” and “continue” indications reflect that thesteps presented can optionally be incorporated in or otherwise used inconjunction with other routines. In this context, “start” indicates thebeginning of the first step presented and may be preceded by otheractivities not specifically shown. Further, the “continue” indicationreflects that the steps presented may be performed multiple times and/ormay be succeeded by other activities not specifically shown. Further,while a flow diagram indicates a particular ordering of steps, otherorderings are likewise possible provided that the principles ofcausality are maintained.

As may also be used herein, the term(s) “operably coupled to”, “coupledto”, and/or “coupling” includes direct coupling between items and/orindirect coupling between items via one or more intervening items. Suchitems and intervening items include, but are not limited to, junctions,communication paths, components, circuit elements, circuits, functionalblocks, and/or devices. As an example of indirect coupling, a signalconveyed from a first item to a second item may be modified by one ormore intervening items by modifying the form, nature or format ofinformation in a signal, while one or more elements of the informationin the signal are nevertheless conveyed in a manner than can berecognized by the second item. In a further example of indirectcoupling, an action in a first item can cause a reaction on the seconditem, as a result of actions and/or reactions in one or more interveningitems.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement which achieves thesame or similar purpose may be substituted for the embodiments describedor shown by the subject disclosure. The subject disclosure is intendedto cover any and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, can be used in the subject disclosure.For instance, one or more features from one or more embodiments can becombined with one or more features of one or more other embodiments. Inone or more embodiments, features that are positively recited can alsobe negatively recited and excluded from the embodiment with or withoutreplacement by another structural and/or functional feature. The stepsor functions described with respect to the embodiments of the subjectdisclosure can be performed in any order. The steps or functionsdescribed with respect to the embodiments of the subject disclosure canbe performed alone or in combination with other steps or functions ofthe subject disclosure, as well as from other embodiments or from othersteps that have not been described in the subject disclosure. Further,more than or less than all of the features described with respect to anembodiment can also be utilized.

What is claimed is:
 1. A method, comprising: generating, by atransmitter, a signal; and inducing, by a coupler, a firstelectromagnetic wave that propagates along a physical transmissionmedium, wherein the coupler has a structure that converts the signalinto a plurality of wave modes that combines to form the firstelectromagnetic wave, and wherein the first electromagnetic wave has afirst electromagnetic field configuration that reduces a leakage of thefirst electromagnetic wave as the first electromagnetic wave propagatesalong the physical transmission medium.
 2. The method of claim 1,wherein the structure of the coupler causes the plurality of wave modesto have a depth of focus that results in the first electromagnetic fieldconfiguration.
 3. The method of claim 1, wherein the structure of thecoupler comprises a non-linear surface.
 4. The method of claim 3,wherein the non-linear surface converts the signal into the plurality ofwave modes.
 5. The method of claim 3, wherein the structure comprises ahollow tapered structure with an inner surface that conforms to thenon-linear surface.
 6. The method of claim 3, wherein the non-linearsurface is metallic.
 7. The method of claim 1, wherein the couplercomprises an aperture formed from a dielectric material that causes theplurality of wave modes to have a depth of focus that results in thefirst electromagnetic field configuration.
 8. The method of claim 7,wherein the dielectric material comprises a plurality of sections, andwherein the plurality of sections has different depths.
 9. The method ofclaim 8, wherein each of the plurality of sections has different frontalwidths defined by a corresponding plurality of radii.
 10. The method ofclaim 9, wherein the different frontal widths and the different depthsof the plurality of sections convert the signal into the plurality ofwave modes having the depth of focus that results in the firstelectromagnetic field configuration.
 11. The method of claim 1, whereinan aperture of the coupler is structurally configured to convert thesignal to the plurality of wave modes.
 12. The method of claim 1,wherein the first electromagnetic wave approximates a Bessel-shapedwaveform.
 13. The method of claim 1, wherein the first electromagneticwave approximates a Bessel-Gauss-shaped waveform.
 14. The method ofclaim 1, further comprising receiving via the coupler a secondelectromagnetic wave propagating along the physical transmission medium,wherein the second electromagnetic wave has a second electromagneticfield configuration that reduces a leakage of the second electromagneticwave as the second electromagnetic wave propagates along the physicaltransmission medium towards the coupler.
 15. A machine-readable medium,comprising executable instructions that, when executed by a processingsystem including a processor, facilitate performance of operations, theoperations comprising: receiving data; and causing a transmitter totransmit a signal that conveys the data, wherein a coupler coupled tothe transmitter converts the signal into a plurality of wave modes thatcombines to form a first electromagnetic wave that propagates along atransmission medium, wherein the first electromagnetic wave has a depthof focus that increases a concentration of electromagnetic fields of thefirst electromagnetic wave, and wherein the concentration ofelectromagnetic fields reduces a leakage of the first electromagneticwave while propagating along the transmission medium.
 16. Themachine-readable medium of claim 15, wherein the coupler comprises anon-linear surface that converts the signal into the plurality of wavemodes.
 17. The machine-readable medium of claim 15, wherein the couplercomprises a structure that converts the signal into the plurality ofwave modes.
 18. A communication device, comprising: a processing systemincluding a processor; and a memory that stores executable instructionsthat, when executed by the processing system, facilitate performance ofoperations, the operations comprising: detecting an obstruction thatincreases a propagation loss of a first electromagnetic wave as thefirst electromagnetic wave propagates along a physical transmissionmedium; and responsive to the detecting, inducing a propagation of asecond electromagnetic wave along the physical transmission medium,wherein the second electromagnetic wave comprises an electromagneticfield configuration, wherein a first portion of the electromagneticfield configuration has a first intensity, wherein a second portion ofthe electromagnetic field configuration has a second intensity, whereinthe first intensity of the first portion of the electromagnetic fieldconfiguration is greater than the second intensity of the second portionof the electromagnetic field configuration, and wherein the firstportion of the electromagnetic field configuration is positioned awayfrom the obstruction to reduce the propagation loss caused by theobstruction.
 19. The communication device of claim 18, wherein thesecond portion of the electromagnetic field configuration enablesguidance of the second electromagnetic wave along the physicaltransmission medium.
 20. The communication device of claim 18, whereinthe second electromagnetic wave is induced by a coupler that produces aplurality of wave modes that combines to form the second electromagneticwave.